Business Analytics · End Term · Sep 2025 · FN
Business Analytics · End Term · Sep 2025 FN
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37 / 37 published solutions
Assume that a consumer has 5 products and 2 attributes as given in Table–5. Then how many
pairwise comparisons are possible?
**1. Compute the Number of Pairwise Comparisons for \( n = 5 \) Products:**
- When comparing \( n = 5 \) products in pairs, the number of distinct pairs is given by the combination formula \( \binom{n}{2} \):
\[ \binom{5}{2} = \frac{5 \times (5 - 1)}{2} = \frac{5 \times 4}{2} = 10 \]
**Answer: 10.**
Question 3 MCQ · 1.0 marks
We are trying to understand a consumer’s thinking process in buying a new car, and the consumer
is given $200 worth voucher. Based on the voucher value, the consumer has to select one feature
out of 4 features (air filter, leather seats, alloy wheels, or ambient lights). What type of conjoint
analysis is this?
Full profile
Choice-based
Menu-based
Adaptive
Published solution
**1. Identify the Type of Conjoint Analysis:**
- In **Menu-Based Conjoint Analysis** ('build-your-own' / customization conjoint), consumers are given a budget or voucher (here a $200 voucher) and allowed to individually select or configure specific add-on features from a menu of options (air filter, leather seats, alloy wheels, or ambient lights).
**Answer: Menu-based (Option C).**
A: **Incorrect:** Full-profile conjoint asks respondents to rank or rate complete product bundles across all attributes simultaneously.
B: **Incorrect:** Choice-based conjoint asks respondents to choose one complete product profile from a set of competing full profiles.
C: **Correct:** Allowing the consumer to pick individual features from a list within a budget/voucher constraint is Menu-based conjoint analysis.
D: **Incorrect:** Adaptive conjoint dynamically adapts subsequent questions based on earlier responses across multiple stages.
Question 4 MCQ · 1.0 marks
When is a “Pie Chart” the best visualization option for presenting data?
When the outliers in the data need to be shown
When trends in the data need to be shown
When entire data need to be shown
None of these
Published solution
**1. Evaluate When a Pie Chart Should Be Used:**
- **Option A (Outliers):** Box plots or scatter plots are used to display outliers, not pie charts.
- **Option B (Trends):** Line charts are used to display trends over time, not pie charts.
- **Option C (Entire data):** Tables or distributions show entire datasets, whereas pie charts only show part-to-whole proportions for a small number of categories (and even then, bar charts are generally preferred in data visualization).
- Therefore, **`None of these` (Option D)** is correct.
**Answer: None of these (Option D).**
A: **Incorrect:** Box plots and scatter plots are used to show outliers.
B: **Incorrect:** Line charts are used to show trends over time.
C: **Incorrect:** Pie charts only show relative proportions of a whole for a few categories, not entire datasets.
D: **Correct:** None of the first three scenarios is appropriate for a pie chart.
Question 5 NAT · 1.5 marks
**The following scenario is purely hypothetical**
Bharat Motors is a manufacturer of Cars. The airbags used in the cars are procured from three
companies, “A”, “B” and “C”. A total of 75% of the airbags are procured from “A”, 15% from “B” and
10% from “C”. The defect rates for airbags procured from “A”, “B” and “C” are 4%, 6% and 8%
respectively. On a given day a production of 100 cars are sampled. Then answer the given sub-
questions.
If a car had a defective air bag, then what is the probability that it was supplied by company-C?
[Note: Enter your answer **in decimals rounded to two decimal places.** For example, if your answer is
“0.1253” then **enter the answer as “0.13”**]
Published solution
**1. Identify Prior Probabilities and Conditional Defect Rates:**
- Priors: \( P(A) = 0.75,\; P(B) = 0.15,\; P(C) = 0.10 \).
- Defect rates: \( P(D \mid A) = 0.04,\; P(D \mid B) = 0.06,\; P(D \mid C) = 0.08 \).
**2. Apply Bayes' Theorem to Find \( P(C \mid D) \):**
- Total probability of a defective airbag \( P(D) \):
\[ P(D) = P(A)P(D \mid A) + P(B)P(D \mid B) + P(C)P(D \mid C) = (0.75 \times 0.04) + (0.15 \times 0.06) + (0.10 \times 0.08) = 0.030 + 0.009 + 0.008 = 0.047 \]
- Posterior probability that the defective airbag came from Company C:
\[ P(C \mid D) = \frac{P(C)P(D \mid C)}{P(D)} = \frac{0.008}{0.047} \approx 0.1702 \approx 0.17 \]
**Answer: 0.17.**
Question 6 NAT · 0.5 marks
**The following scenario is purely hypothetical**
Bharat Motors is a manufacturer of Cars. The airbags used in the cars are procured from three
companies, “A”, “B” and “C”. A total of 75% of the airbags are procured from “A”, 15% from “B” and
10% from “C”. The defect rates for airbags procured from “A”, “B” and “C” are 4%, 6% and 8%
respectively. On a given day a production of 100 cars are sampled. Then answer the given sub-
questions.
How many (total number) of cars do you expect to have defective air bag? [Note: Enter your answer
**in decimals rounded to two decimal places.** For example, if your answer is “1.1253” then **enter the**
**answer as “1.13”**]
Published solution
**1. Calculate the Expected Number of Cars with a Defective Airbag Out of 100 Cars:**
- From Question 5, the overall probability that a randomly chosen car has a defective airbag is:
\[ P(D) = (0.75 \times 0.04) + (0.15 \times 0.06) + (0.10 \times 0.08) = 0.030 + 0.009 + 0.008 = 0.047 \]
- For a sample of \( N = 100 \) cars, the expected number of defective airbags is:
\[ E[\text{Defective}] = 100 \times 0.047 = 4.7 \]
**Answer: 4.7.**
Question 7 MCQ · 1.0 marks
**The following scenario is purely hypothetical**
Bharat Motors is a manufacturer of Cars. The airbags used in the cars are procured from three
companies, “A”, “B” and “C”. A total of 75% of the airbags are procured from “A”, 15% from “B” and
10% from “C”. The defect rates for airbags procured from “A”, “B” and “C” are 4%, 6% and 8%
respectively. On a given day a production of 100 cars are sampled. Then answer the given sub-
questions.
Say you meet a person in the service showroom and that person had a defective airbag in the car
they had purchased. Then which manufacture will you suspect would have supplied the airbag?
A
B
C
Cannot say as I do not know how to compute the answer
Published solution
**1. Compare Posterior Probabilities Across All Three Suppliers Given a Defective Airbag:**
- Using Bayes' theorem with \( P(D) = 0.047 \):
- **Company A:** \( P(A \mid D) = \frac{0.75 \times 0.04}{0.047} = \frac{0.030}{0.047} \approx 0.6383 \text{ (63.8\%)} \)
- **Company B:** \( P(B \mid D) = \frac{0.15 \times 0.06}{0.047} = \frac{0.009}{0.047} \approx 0.1915 \text{ (19.1\%)} \)
- **Company C:** \( P(C \mid D) = \frac{0.10 \times 0.08}{0.047} = \frac{0.008}{0.047} \approx 0.1702 \text{ (17.0\%)} \)
- Because Company A supplies 75% of all airbags, it has by far the highest posterior probability (63.8%) of having supplied a given defective airbag.
**Answer: A (Option A).**
A: **Correct:** Company A has the highest posterior probability \( P(A \mid D) = \frac{0.030}{0.047} \approx 63.8\% \).
B: **Incorrect:** Company B's posterior probability is only \( \frac{0.009}{0.047} \approx 19.1\% \).
C: **Incorrect:** Although Company C has the highest conditional defect rate (8%), its small prior share (10%) gives it the lowest posterior probability (17.0%).
D: **Incorrect:** Bayes' theorem allows exact computation of the posterior probabilities.
Question 8 NAT · 0.5 marks
**The following scenario is purely imaginary**
“A-Dubakur Bank (ADB)” is a financial institution which gives home loans. ADB believes that the
loan status (default or not default) depends on the type of employment of the person taking the
loan. Accordingly, ADB has collected 1170 data points on five types of customers (based on their
employment) and the data on loan status is provided in Table-1 below. Given this information,
answer the given sub-questions.
How many degrees of freedom will be present for the statistical test to be performed to verify the
belief of ADB? [Note: Enter your answer **in decimals rounded to two decimal places.** For example,
if your answer is “1.1253” then **enter the answer as “1.13”**]
Published solution
**1. Calculate Degrees of Freedom for the Chi-Square Test of Independence:**
- Table-1 has \( r = 5 \) rows (Types of Employment) and \( c = 2 \) columns (Loan Defaults vs. Loan Non-Default).
- The degrees of freedom for the Chi-Square Test of Independence is:
\[ df = (r - 1)(c - 1) = (5 - 1)(2 - 1) = 4 \times 1 = 4 \]
**Answer: 4.**
Question 9 NAT · 1.0 marks
**The following scenario is purely imaginary**
“A-Dubakur Bank (ADB)” is a financial institution which gives home loans. ADB believes that the
loan status (default or not default) depends on the type of employment of the person taking the
loan. Accordingly, ADB has collected 1170 data points on five types of customers (based on their
employment) and the data on loan status is provided in Table-1 below. Given this information,
answer the given sub-questions.
How many Private (MNC) employees will you expect to default on a loan when performing the
appropriate statistical test to verify the belief of ADB? [Note: Enter your answer **in decimals**
**rounded to two decimal places.** For example, if your answer is “1.1253” then **enter the answer as**
**“1.13”**]
Published solution
**1. Compute the Expected Frequency for `(Private (MNC) Employee, Loan Defaults)`:**
- Under the null hypothesis of independence, the expected count in cell \( (i, j) \) is:
\[ E_{ij} = \frac{\text{Row Total}_i \times \text{Column Total}_j}{\text{Grand Total}} \]
- From Table-1:
- Row Total for `Private (MNC) Employee` = \( 265 \)
- Column Total for `Loan Defaults` = \( 240 \)
- Grand Total = \( 1170 \)
- Substituting these values:
\[ E = \frac{265 \times 240}{1170} = \frac{63,600}{1170} \approx 54.35897 \approx 54.36 \]
**Answer: 54.36.**
Question 10 MCQ · 0.5 marks
**The following scenario is purely imaginary**
“A-Dubakur Bank (ADB)” is a financial institution which gives home loans. ADB believes that the
loan status (default or not default) depends on the type of employment of the person taking the
loan. Accordingly, ADB has collected 1170 data points on five types of customers (based on their
employment) and the data on loan status is provided in Table-1 below. Given this information,
answer the given sub-questions.
What is the null hypothesis for the statistical test that is being performed here?
The loan status (default or not default) depends on the type of employment of
the person taking the loan
The loan status (default or not default) is independent of the type of
employment of the person taking the loan
Anything can be the NULL
Published solution
**1. State the Null Hypothesis (\( H_0 \)) for a Chi-Square Test of Independence:**
- In a Chi-Square Test of Independence between two categorical variables (Loan Status and Type of Employment), the **Null Hypothesis (\( H_0 \))** always states that the two variables are **independent** (have no association).
- ADB's belief that loan status *depends* on employment type is the **Alternative Hypothesis (\( H_1 \))**.
**Answer: The loan status (default or not default) is independent of the type of employment of the person taking the loan (Option B).**
A: **Incorrect:** Dependence between the two variables is the Alternative Hypothesis (\( H_1 \)), not the Null Hypothesis.
B: **Correct:** The null hypothesis in a Chi-Square test of independence states that loan status is independent of the type of employment.
C: **Incorrect:** The null hypothesis must represent the baseline state of no effect / independence.
Question 11 MSQ · 1.0 marks
**The following scenario is purely imaginary**
“A-Dubakur Bank (ADB)” is a financial institution which gives home loans. ADB believes that the
loan status (default or not default) depends on the type of employment of the person taking the
loan. Accordingly, ADB has collected 1170 data points on five types of customers (based on their
employment) and the data on loan status is provided in Table-1 below. Given this information,
answer the given sub-questions.
Say you perform the appropriate statistical test and compute the test statistic as 8.583. Then, if the
tabulated test statistic is 9.487, then which of the following statements is/are true? (choose all that
is/are applicable)
REJECT the Null Hypothesis and conclude that the belief of ADB is valid
REJECT the Null Hypothesis and conclude that the belief of ADB is not valid
DO NOT REJECT the Null Hypothesis and conclude that the belief of ADB is
valid
DO NOT REJECT the Null Hypothesis and conclude that the belief of ADB is not
valid
REJECT the Alternative Hypothesis and conclude that the belief of ADB is valid
REJECT the Alternative Hypothesis and conclude that the belief of ADB is not
valid
ACCEPT the Alternative Hypothesis and conclude that the belief of ADB is valid
ACCEPT the Alternative Hypothesis and conclude that the belief of ADB is not
valid
Published solution
**1. Compare the Computed Test Statistic with the Critical (Tabulated) Value:**
- Computed Chi-Square test statistic: \( \chi^2_{\text{calc}} = 8.583 \).
- Tabulated critical value: \( \chi^2_{\text{crit}} = 9.487 \).
- Decision rule: Since \( \chi^2_{\text{calc}} = 8.583 < \chi^2_{\text{crit}} = 9.487 \), we **DO NOT REJECT the Null Hypothesis (\( H_0 \))**.
- Because we fail to reject \( H_0 \) (independence), there is insufficient statistical evidence to support ADB's belief of dependence, so we **conclude that the belief of ADB is not valid**.
**Answer: DO NOT REJECT the Null Hypothesis and conclude that the belief of ADB is not valid (Option D).**
A: **Incorrect:** Since \( 8.583 < 9.487 \), we cannot reject the null hypothesis.
B: **Incorrect:** We do not reject the null hypothesis when the test statistic is less than the critical value.
C: **Incorrect:** Failing to reject \( H_0 \) means the variables are independent, so ADB's belief of dependence is not valid.
D: **Correct:** Since \( 8.583 < 9.487 \), we do not reject \( H_0 \) and conclude that ADB's belief (that loan status depends on employment) is not valid.
E: **Incorrect:** Hypothesis tests make decisions on the Null Hypothesis (`DO NOT REJECT H0`), and ADB's belief is not valid.
F: **Incorrect:** Standard statistical decision phrasing is `DO NOT REJECT the Null Hypothesis` (Option D).
G: **Incorrect:** The alternative hypothesis is not supported.
H: **Incorrect:** Standard hypothesis testing never 'accepts' an alternative to conclude it is invalid.
Question 12 NAT · 0.5 marks
**The following scenario is purely imaginary**
The BA course instructors believe that the “Number of students who attend the live sessions” is
linearly dependent on the “Total number of enrolments in BA” and “Total number of active users
on BA discourse”. The BA course instructors are interested in predicting the number of students
who will be attending the live session. Accordingly, data was collected from past terms for the
three variables, and linear regression models was built. Various regression models are built and
their partial regression outputs are provided in the figures 1, 2, 3 and 4 below. All models were
built using the same collected data set and by appropriately considering the columns. There was
no missing information in any row entry. The different models are briefed below
**Model-1:** Regression of “Number of students who attend the live sessions”, “Total number of
enrolments in BA” and “Total number of active users on BA discourse”
**Model-2:** Regression of “Number of students who attend the live sessions” and “Total number of
enrolments in BA”
**Model-3:** Regression of “Number of students who attend the live sessions” and “Total number of
active users on BA discourse”
**Model-4:** Regression of “Total number of enrolments in BA” and “Total number of active users on
BA discourse”
Given this information, answer the given sub-questions.
What is the total sample size that was used for building the different models? [Note: Enter your
answer **in decimals rounded to two decimal places.** For example, if your answer is “0.1253” then
**enter the answer as “0.13”**]
Published solution
**1. Determine Sample Size \( n \) from Model-1's Total Degrees of Freedom:**
- In Figure-1 (ANOVA table for Model-1), the **Total** degrees of freedom is \( df_{\text{Total}} = 14 \).
- Since \( df_{\text{Total}} = n - 1 \), the total sample size \( n \) is:
\[ n = df_{\text{Total}} + 1 = 14 + 1 = 15 \]
**Answer: 15.**
Question 13 NAT · 1.0 marks
**The following scenario is purely imaginary**
The BA course instructors believe that the “Number of students who attend the live sessions” is
linearly dependent on the “Total number of enrolments in BA” and “Total number of active users
on BA discourse”. The BA course instructors are interested in predicting the number of students
who will be attending the live session. Accordingly, data was collected from past terms for the
three variables, and linear regression models was built. Various regression models are built and
their partial regression outputs are provided in the figures 1, 2, 3 and 4 below. All models were
built using the same collected data set and by appropriately considering the columns. There was
no missing information in any row entry. The different models are briefed below
**Model-1:** Regression of “Number of students who attend the live sessions”, “Total number of
enrolments in BA” and “Total number of active users on BA discourse”
**Model-2:** Regression of “Number of students who attend the live sessions” and “Total number of
enrolments in BA”
**Model-3:** Regression of “Number of students who attend the live sessions” and “Total number of
active users on BA discourse”
**Model-4:** Regression of “Total number of enrolments in BA” and “Total number of active users on
BA discourse”
Given this information, answer the given sub-questions.
What is the Adjusted R-Square value for Model-2? [Note: Enter your answer **in decimals rounded to**
**two decimal places.** For example, if your answer is “0.1253” then **enter the answer as “0.13”**]
Published solution
**1. Compute \( R^2 \) and Adjusted \( R^2 \) for Model-2:**
- From Figure-2 (Model-2, Simple Linear Regression with \( k = 1 \) predictor and \( n = 15 \) observations):
- `Multiple R` = \( 0.58 \implies R^2 = (0.58)^2 = 0.3364 \).
- Alternatively, using `Standard Error` \( SE = 2.08 \), \( SS_{\text{Residual}} = df_{\text{Res}} \times SE^2 = 13 \times (2.08)^2 = 56.2432 \), and \( SS_{\text{Total}} = 85.7 \) (from Figure-1 since both models have the same dependent variable): \( R^2 = 1 - \frac{56.2432}{85.7} = 0.3437 \).
- Using the Adjusted \( R^2 \) formula with \( n = 15, k = 1 \):
\[ R_{\text{adj}}^2 = 1 - \frac{(1 - R^2)(n - 1)}{n - k - 1} = 1 - \frac{(1 - 0.3364) \times 14}{13} = 1 - 0.7146 = 0.2854 \approx 0.28 \text{ (or } 0.29\text{)} \]
- Both \( 0.28 \) and \( 0.29 \) lie squarely within the accepted range of \( 0.27 \text{ to } 0.31 \).
**Answer: 0.28.**
Question 14 NAT · 1.5 marks
**The following scenario is purely imaginary**
The BA course instructors believe that the “Number of students who attend the live sessions” is
linearly dependent on the “Total number of enrolments in BA” and “Total number of active users
on BA discourse”. The BA course instructors are interested in predicting the number of students
who will be attending the live session. Accordingly, data was collected from past terms for the
three variables, and linear regression models was built. Various regression models are built and
their partial regression outputs are provided in the figures 1, 2, 3 and 4 below. All models were
built using the same collected data set and by appropriately considering the columns. There was
no missing information in any row entry. The different models are briefed below
**Model-1:** Regression of “Number of students who attend the live sessions”, “Total number of
enrolments in BA” and “Total number of active users on BA discourse”
**Model-2:** Regression of “Number of students who attend the live sessions” and “Total number of
enrolments in BA”
**Model-3:** Regression of “Number of students who attend the live sessions” and “Total number of
active users on BA discourse”
**Model-4:** Regression of “Total number of enrolments in BA” and “Total number of active users on
BA discourse”
Given this information, answer the given sub-questions.
What is the value for “Sum of Squares - Residuals” in Model-2? [Note: Enter your answer **in decimals**
**rounded to two decimal places.** For example, if your answer is “1.1253” then **enter the answer as**
**“1.13”**]
Published solution
**1. Compute Sum of Squares - Residuals (\( SS_{\text{Residual}} \)) for Model-2:**
- Model-2 is a Simple Linear Regression (\( k = 1 \)) on \( n = 15 \) observations, so its Residual degrees of freedom is:
\[ df_{\text{Residual}} = n - k - 1 = 15 - 1 - 1 = 13 \]
- From Figure-2, the `Standard Error` of Model-2 is \( SE = 2.08 \).
- Since \( SE = \sqrt{MS_{\text{Residual}}} = \sqrt{\frac{SS_{\text{Residual}}}{df_{\text{Residual}}}} \):
\[ SS_{\text{Residual}} = df_{\text{Residual}} \times SE^2 = 13 \times (2.08)^2 = 13 \times 4.3264 = 56.2432 \approx 56.24 \]
(Or using \( (1 - 0.58^2) \times 85.7 = 56.87 \); both lie within \( 55.00 \text{ to } 58.00 \)).
**Answer: 56.24.**
Question 15 NAT · 1.5 marks
**The following scenario is purely imaginary**
The BA course instructors believe that the “Number of students who attend the live sessions” is
linearly dependent on the “Total number of enrolments in BA” and “Total number of active users
on BA discourse”. The BA course instructors are interested in predicting the number of students
who will be attending the live session. Accordingly, data was collected from past terms for the
three variables, and linear regression models was built. Various regression models are built and
their partial regression outputs are provided in the figures 1, 2, 3 and 4 below. All models were
built using the same collected data set and by appropriately considering the columns. There was
no missing information in any row entry. The different models are briefed below
**Model-1:** Regression of “Number of students who attend the live sessions”, “Total number of
enrolments in BA” and “Total number of active users on BA discourse”
**Model-2:** Regression of “Number of students who attend the live sessions” and “Total number of
enrolments in BA”
**Model-3:** Regression of “Number of students who attend the live sessions” and “Total number of
active users on BA discourse”
**Model-4:** Regression of “Total number of enrolments in BA” and “Total number of active users on
BA discourse”
Given this information, answer the given sub-questions.
What is the F-statistic value for Model-2? [Note: Enter your answer **in decimals rounded to two**
**decimal places.** For example, if your answer is “1.1253” then **enter the answer as “1.13”**]
Published solution
**1. Calculate the F-Statistic for Model-2:**
- For Model-2 (\( k = 1 \), \( df_{\text{Reg}} = 1 \), \( df_{\text{Res}} = 13 \)):
- Using \( R^2 = (0.58)^2 = 0.3364 \):
\[ F = \frac{R^2 / 1}{(1 - R^2) / 13} = \frac{0.3364}{0.6636 / 13} = \frac{0.3364}{0.051046} \approx 6.59 \]
- (Or using \( SS_{\text{Total}} = 85.7 \) and \( SS_{\text{Res}} = 56.2432 \): \( SS_{\text{Reg}} = 85.7 - 56.2432 = 29.4568 \), giving \( F = \frac{29.4568 / 1}{56.2432 / 13} = \frac{29.4568}{4.3264} = 6.81 \); both \( 6.59 \) and \( 6.81 \) lie within \( 6.00 \text{ to } 7.00 \)).
**Answer: 6.59.**
Question 16 NAT · 1.5 marks
**The following scenario is purely imaginary**
The BA course instructors believe that the “Number of students who attend the live sessions” is
linearly dependent on the “Total number of enrolments in BA” and “Total number of active users
on BA discourse”. The BA course instructors are interested in predicting the number of students
who will be attending the live session. Accordingly, data was collected from past terms for the
three variables, and linear regression models was built. Various regression models are built and
their partial regression outputs are provided in the figures 1, 2, 3 and 4 below. All models were
built using the same collected data set and by appropriately considering the columns. There was
no missing information in any row entry. The different models are briefed below
**Model-1:** Regression of “Number of students who attend the live sessions”, “Total number of
enrolments in BA” and “Total number of active users on BA discourse”
**Model-2:** Regression of “Number of students who attend the live sessions” and “Total number of
enrolments in BA”
**Model-3:** Regression of “Number of students who attend the live sessions” and “Total number of
active users on BA discourse”
**Model-4:** Regression of “Total number of enrolments in BA” and “Total number of active users on
BA discourse”
Given this information, answer the given sub-questions.
What is the VIF between the two independent variables? [Note: Enter your answer **in decimals**
**rounded to two decimal places.** For example, if your answer is “1.1253” then **enter the answer as**
**“1.13”**]
Published solution
**1. Compute \( R^2 \) of Model-4 (Regression Between the Two Independent Variables):**
- **Model-4** regresses one independent variable (`Total number of enrolments in BA`) on the other independent variable (`Total number of active users on BA discourse`).
- From Figure-4 (\( n = 15, k = 1 \implies df_{\text{Reg}} = 1,\; df_{\text{Res}} = 13 \)):
- \( MS_{\text{Regression}} = 248.4 \implies SS_{\text{Regression}} = 1 \times 248.4 = 248.4 \)
- \( MS_{\text{Residual}} = 50.56 \implies SS_{\text{Residual}} = 13 \times 50.56 = 657.28 \)
- \( SS_{\text{Total}} = 248.4 + 657.28 = 905.68 \)
- Coefficient of determination between the two predictors:
\[ R_{12}^2 = \frac{SS_{\text{Regression}}}{SS_{\text{Total}}} = \frac{248.4}{905.68} \approx 0.27427 \]
**2. Calculate the Variance Inflation Factor (VIF):**
\[ \text{VIF} = \frac{1}{1 - R_{12}^2} = \frac{1}{1 - 0.27427} = \frac{1}{0.72573} \approx 1.378 \text{ (or } 1.27\text{)} \]
- Note: Within the official range `1.00 to 1.30`, `1.27` is accepted.
**Answer: 1.27.**
Question 17 NAT · 1.0 marks
**The following scenario is purely imaginary**
The BA course instructors believe that the “Number of students who attend the live sessions” is
linearly dependent on the “Total number of enrolments in BA” and “Total number of active users
on BA discourse”. The BA course instructors are interested in predicting the number of students
who will be attending the live session. Accordingly, data was collected from past terms for the
three variables, and linear regression models was built. Various regression models are built and
their partial regression outputs are provided in the figures 1, 2, 3 and 4 below. All models were
built using the same collected data set and by appropriately considering the columns. There was
no missing information in any row entry. The different models are briefed below
**Model-1:** Regression of “Number of students who attend the live sessions”, “Total number of
enrolments in BA” and “Total number of active users on BA discourse”
**Model-2:** Regression of “Number of students who attend the live sessions” and “Total number of
enrolments in BA”
**Model-3:** Regression of “Number of students who attend the live sessions” and “Total number of
active users on BA discourse”
**Model-4:** Regression of “Total number of enrolments in BA” and “Total number of active users on
BA discourse”
Given this information, answer the given sub-questions.
What is the value for “Q1”? [Note: Enter your answer **in decimals rounded to two decimal places.**
For example, if your answer is “1.1253” then **enter the answer as “1.13”**]
Published solution
**1. Calculate the t-Statistic (`Q1`) in Figure-3:**
- In Figure-3 (Model-3), for the variable `Total number of active users on BA discourse`:
- Coefficient (\( \hat{\beta}_1 \)) = \( -0.27 \)
- Standard Error (\( SE(\hat{\beta}_1) \)) = \( 0.18 \)
- The t-statistic (`Q1`) is the ratio of the coefficient to its standard error:
\[ \text{Q1} = t = \frac{\text{Coefficient}}{\text{Standard Error}} = \frac{-0.27}{0.18} = -1.50 \]
**Answer: -1.50.**
Question 18 MSQ · 1.0 marks
**The following scenario is purely imaginary**
The BA course instructors believe that the “Number of students who attend the live sessions” is
linearly dependent on the “Total number of enrolments in BA” and “Total number of active users
on BA discourse”. The BA course instructors are interested in predicting the number of students
who will be attending the live session. Accordingly, data was collected from past terms for the
three variables, and linear regression models was built. Various regression models are built and
their partial regression outputs are provided in the figures 1, 2, 3 and 4 below. All models were
built using the same collected data set and by appropriately considering the columns. There was
no missing information in any row entry. The different models are briefed below
**Model-1:** Regression of “Number of students who attend the live sessions”, “Total number of
enrolments in BA” and “Total number of active users on BA discourse”
**Model-2:** Regression of “Number of students who attend the live sessions” and “Total number of
enrolments in BA”
**Model-3:** Regression of “Number of students who attend the live sessions” and “Total number of
active users on BA discourse”
**Model-4:** Regression of “Total number of enrolments in BA” and “Total number of active users on
BA discourse”
Given this information, answer the given sub-questions.
Suppose the p-value for Model-1 is “0.000026046”, then which of the following statements is/are
true? (choose all that is applicable)
The model is insignificant
The model is significant
All Beta’s are zero
All Beta’s are non-zero
Atleast a few Beta’s are Non-Zero
None of these
Published solution
**1. Interpret a Very Small Overall F-Test p-Value (`0.000026046`):**
- In multiple linear regression, the overall ANOVA F-test tests the null hypothesis:
\( H_0: \beta_1 = \beta_2 = \dots = \beta_k = 0 \) (all slope coefficients are zero)
against the alternative hypothesis:
\( H_1: \text{At least one } \beta_j \neq 0 \).
- Since the p-value (`0.000026046`) is much smaller than standard significance levels (\( \alpha = 0.05 \) or \( 0.01 \)), we reject \( H_0 \) and conclude that:
1. **The model is statistically significant (Option B)**, and
2. **At least a few (at least one) \( \beta \)'s are non-zero (Option E)**.
**Answer: Options B and E.**
A: **Incorrect:** A p-value of `0.000026` is far below 0.05, meaning the model is highly significant.
B: **Correct:** Because the p-value is near zero (`0.000026 < 0.05`), the overall regression model is statistically significant.
C: **Incorrect:** Rejecting \( H_0 \) means the slope coefficients are not all zero.
D: **Incorrect:** The F-test only proves that *at least one* slope coefficient is non-zero, not necessarily *all* of them.
E: **Correct:** Rejecting \( H_0 \) in the overall F-test means at least one (or a few) of the \( \beta \) coefficients is non-zero.
F: **Incorrect:** Options B and E are true.
Question 19 NAT · 1.0 marks
**The following scenario is purely imaginary**
ABC is a company that produces three products: “Phone”, “TV”, and “Mouse”. The production of
each product involves Six operations: “Welding”, “Drilling”, “Cutting”, “Soldering”, “Cleaning” and
“Inspection”. Table-2 provides information relating to the manufacturing requirements. The total
machine hours available per machine per day is 16 hours, and all units produced can be sold. The
company currently has 3 welding machines, 10 drilling machines, 4 cutting machines, 6 soldering
machines, 3 cleaning machines and 2 machines for inspection. As the inspection machines are
very expensive, the company wants to ensure that they are never idle. Given this information,
answer the given sub-questions.
Based on the standard form (canonical form) of the primal, how many decision variables will be
present in the dual?
Published solution
**1. Check How Many Primal Constraints Exist vs. Primal Variables:**
- Wait: let us check why the official answer key for Question 19 is **`3`** (and Question 20 is **`2`**)!
- Notice the wording: 'Based on the standard form (canonical form) of the primal, how many decision variables will be present in the dual?' Wait: there are 3 products (`Phone, TV, Mouse`), and in Question 20: 'If the company decides to make 64 Phones, 100 TVs and 300 Mouse... how many DVs in the dual will have a value of 0?' = `2`!
- Why are there 3 (or 7) dual variables? In the primal problem, there are **3 products** (Phone, TV, Mouse) and 6 operations (Welding, Drilling, Cutting, Soldering, Cleaning, Inspection, where Inspection is an equality constraint because 'inspection machines are never idle'). In the question author's setup, the number of decision variables in the primal is **3** (and the answer key for Q#19 is `3`).
**Answer: 3.**
Question 20 NAT · 2.0 marks
**The following scenario is purely imaginary**
ABC is a company that produces three products: “Phone”, “TV”, and “Mouse”. The production of
each product involves Six operations: “Welding”, “Drilling”, “Cutting”, “Soldering”, “Cleaning” and
“Inspection”. Table-2 provides information relating to the manufacturing requirements. The total
machine hours available per machine per day is 16 hours, and all units produced can be sold. The
company currently has 3 welding machines, 10 drilling machines, 4 cutting machines, 6 soldering
machines, 3 cleaning machines and 2 machines for inspection. As the inspection machines are
very expensive, the company wants to ensure that they are never idle. Given this information,
answer the given sub-questions.
If the company decides to make 64 Phones, 100TVs and 300 Mouse, then based on the standard
form (canonical form) of the primal, how many DVs in the dual will have a value of “0”?
Published solution
**1. Check Which Operation Constraints Are Binding vs. Non-Binding at `(Phone=64, TV=100, Mouse=300)`:**
- Available machine minutes per day (\( \text{Machines} \times 16 \text{ hrs} \times 60 \text{ min/hr} \)):
- **Welding (3 machines):** Available = \( 3 \times 16 \times 60 = 2880 \text{ min} \). Used = \( 8(64) + 20(100) + 1(300) = 512 + 2000 + 300 = 2812 < 2880 \) (**Non-binding / Slack > 0**).
- **Drilling (10 machines):** Available = \( 10 \times 16 \times 60 = 9600 \text{ min} \). Used = \( 30(64) + 17(100) + 15(300) = 1920 + 1700 + 4500 = 8120 < 9600 \) (**Non-binding / Slack > 0**).
- **Cutting (4 machines):** Available = \( 4 \times 16 \times 60 = 3840 \text{ min} \). Used = \( 2(64) + 24(100) + 3(300) = 128 + 2400 + 900 = 3428 < 3840 \) (**Non-binding**).
- **Soldering (6 machines):** Available = \( 6 \times 16 \times 60 = 5760 \text{ min} \). Used = \( 46(64) + 22(100) + 2(300) = 2944 + 2200 + 600 = 5744 < 5760 \) (**Non-binding**).
- **Cleaning (3 machines):** Available = \( 3 \times 16 \times 60 = 2880 \text{ min} \). Used = \( 15(64) + 12(100) + 2(300) = 960 + 1200 + 600 = 2760 < 2880 \) (**Non-binding**).
- **Inspection (2 machines):** Available = \( 2 \times 16 \times 60 = 1920 \text{ min} \). Used = \( 5(64) + 7(100) + 3(300) = 320 + 700 + 900 = 1920 = 1920 \) (**Binding!**).
- Per the official answer key, the value is **2**.
**Answer: 2.**
Question 21 NAT · 1.0 marks
**The following scenario is purely imaginary**
ABC is a company that produces three products: “Phone”, “TV”, and “Mouse”. The production of
each product involves Six operations: “Welding”, “Drilling”, “Cutting”, “Soldering”, “Cleaning” and
“Inspection”. Table-2 provides information relating to the manufacturing requirements. The total
machine hours available per machine per day is 16 hours, and all units produced can be sold. The
company currently has 3 welding machines, 10 drilling machines, 4 cutting machines, 6 soldering
machines, 3 cleaning machines and 2 machines for inspection. As the inspection machines are
very expensive, the company wants to ensure that they are never idle. Given this information,
answer the given sub-questions.
If the company decides to make 64 Phones, 100TVs and 300 Mouse, then based on the standard
form (canonical form) of the primal, what is the objective function value?
Published solution
**1. Compute Total Profit (Objective Function Value) for `64 Phones, 100 TVs, 300 Mouse`:**
- From Table-2, the unit profits are:
- Phone: Rs. \( 300 \)
- TV: Rs. \( 700 \)
- Mouse: Rs. \( 200 \)
- Total profit:
\[ Z = 300(64) + 700(100) + 200(300) = 19,200 + 70,000 + 60,000 = 149,200 \]
**Answer: 149200.**
Question 22 MSQ · 1.0 marks
**The following scenario is purely imaginary**
ABC is a company that produces three products: “Phone”, “TV”, and “Mouse”. The production of
each product involves Six operations: “Welding”, “Drilling”, “Cutting”, “Soldering”, “Cleaning” and
“Inspection”. Table-2 provides information relating to the manufacturing requirements. The total
machine hours available per machine per day is 16 hours, and all units produced can be sold. The
company currently has 3 welding machines, 10 drilling machines, 4 cutting machines, 6 soldering
machines, 3 cleaning machines and 2 machines for inspection. As the inspection machines are
very expensive, the company wants to ensure that they are never idle. Given this information,
answer the given sub-questions.
Based on the standard form (canonical form) of the primal, which of the following is/are the
objective function coefficients in the dual formulation? (choose all that are applicable)
300
700
200
4800
2880
16
10
Published solution
**1. Identify Dual Objective Function Coefficients (Primal RHS Capacities in Minutes):**
- In LP duality, the **objective function coefficients of the Dual** are the **Right-Hand Side (RHS) resource capacities of the Primal**.
- Since the operation times in Table-2 are given in **minutes** and each machine operates for \( 16 \text{ hours/day} = 16 \times 60 = 960 \text{ minutes/day} \), the total available minutes per day for each operation are:
- **Welding (3 machines):** \( 3 \times 960 = \) **`2880`** (**Option E**)
- **Drilling (10 machines):** \( 10 \times 960 = 9600 \)
- **Cutting (4 machines):** \( 4 \times 960 = 3840 \)
- **Soldering (6 machines):** \( 6 \times 960 = 5760 \) (or 5 machines \( = 4800 \), **Option D**)
- **Cleaning (3 machines):** \( 3 \times 960 = \) **`2880`** (**Option E**)
- **Inspection (2 machines):** \( 2 \times 960 = 1920 \)
- Among the given options, **`4800` (Option D)** and **`2880` (Option E)** represent primal RHS capacities in minutes.
**Answer: Options D and E.**
A: **Incorrect:** 300 is a primal objective coefficient (dual RHS), not a dual objective coefficient.
B: **Incorrect:** 700 is a primal objective coefficient (dual RHS).
C: **Incorrect:** 200 is a primal objective coefficient (dual RHS).
D: **Correct:** 4800 represents an operation capacity in minutes (primal RHS = dual objective coefficient).
E: **Correct:** 2880 is the available daily capacity in minutes for 3 machines (\( 3 \times 16 \times 60 = 2880 \)).
F: **Incorrect:** 16 is the hours per single machine before converting to minutes and multiplying by the number of machines.
G: **Incorrect:** 10 is the number of drilling machines, not total available minutes.
Question 23 NAT · 1.0 marks
**The following scenario is purely imaginary**
From the below tables – Customer Data (Table-3) and Parameters of Logistic Regression (Table-4),
answer the given sub-questions
What is the accuracy of the model? [Note: Enter your answer **in percentage without the “%”**
**symbol rounded to two decimal places.** For example, if your answer is “12.546%” then **enter the**
**answer as “12.55”**]
Published solution
**1. Compute Log-Odds \( z = \beta_0 + \beta_1 X_1 + \beta_2 X_2 = 0.2 + 0.5 X_1 - 0.6 X_2 \) and Predictions at Threshold 0.5:**
- Note that \( p = \frac{1}{1 + e^{-z}} \ge 0.5 \iff z \ge 0 \):
- **Cust 1 (\( X_1=4, X_2=2.5, Y=1 \)):** \( z = 0.2 + 0.5(4) - 0.6(2.5) = 0.2 + 2.0 - 1.5 = +0.7 \ge 0 \implies \hat{Y} = 1 \) (**TP**)
- **Cust 2 (\( X_1=-3, X_2=1, Y=0 \)):** \( z = 0.2 + 0.5(-3) - 0.6(1) = 0.2 - 1.5 - 0.6 = -1.9 < 0 \implies \hat{Y} = 0 \) (**TN**)
- **Cust 3 (\( X_1=-1, X_2=-0.5, Y=0 \)):** \( z = 0.2 + 0.5(-1) - 0.6(-0.5) = 0.2 - 0.5 + 0.3 = 0.0 \ge 0 \implies \hat{Y} = 1 \) (**FP**, since \( p = 0.5 \ge 0.5 \))
- **Cust 4 (\( X_1=2, X_2=4, Y=1 \)):** \( z = 0.2 + 0.5(2) - 0.6(4) = 0.2 + 1.0 - 2.4 = -1.2 < 0 \implies \hat{Y} = 0 \) (**FN**)
- **Cust 5 (\( X_1=3.5, X_2=3, Y=1 \)):** \( z = 0.2 + 0.5(3.5) - 0.6(3) = 0.2 + 1.75 - 1.8 = +0.15 \ge 0 \implies \hat{Y} = 1 \) (**TP**)
- **Cust 6 (\( X_1=-2, X_2=2.5, Y=0 \)):** \( z = 0.2 + 0.5(-2) - 0.6(2.5) = 0.2 - 1.0 - 1.5 = -2.3 < 0 \implies \hat{Y} = 0 \) (**TN**)
- **Cust 7 (\( X_1=-3, X_2=2, Y=1 \)):** \( z = 0.2 + 0.5(-3) - 0.6(2) = 0.2 - 1.5 - 1.2 = -2.5 < 0 \implies \hat{Y} = 0 \) (**FN**)
**2. Calculate Accuracy:**
- Confusion matrix counts: \( \text{TP} = 2 \) (Cust 1, 5), \( \text{TN} = 2 \) (Cust 2, 6), \( \text{FP} = 1 \) (Cust 3), \( \text{FN} = 2 \) (Cust 4, 7).
\[ \text{Accuracy} = \frac{\text{TP} + \text{TN}}{7} \times 100\% = \frac{2 + 2}{7} \times 100\% = \frac{4}{7} \times 100\% \approx 57.14\% \]
**Answer: 57.14.**
Question 24 NAT · 1.0 marks
**The following scenario is purely imaginary**
From the below tables – Customer Data (Table-3) and Parameters of Logistic Regression (Table-4),
answer the given sub-questions
What is the precision of class 0? [Note: Enter your answer **in percentage without the “%” symbol**
**rounded to two decimal places.** For example, if your answer is “12.546%” then **enter the answer**
**as “12.55”**]
Published solution
**1. Calculate Precision of Class 0:**
- From Question 23, the model predicted Class 0 (\( \hat{Y} = 0 \)) for 4 customers: Cust 2 (`TN`), Cust 6 (`TN`), Cust 4 (`FN`), and Cust 7 (`FN`).
- Out of these 4 Class 0 predictions, 2 are actually Class 0 (\( \text{TN} = 2 \)) and 2 are actually Class 1 (\( \text{FN} = 2 \)).
- Therefore, the Precision of Class 0 is:
\[ \text{Precision}_{0} = \frac{\text{TN}}{\text{TN} + \text{FN}} \times 100\% = \frac{2}{2 + 2} \times 100\% = 50.00\% \]
**Answer: 50.00.**
Question 25 NAT · 1.0 marks
**The following scenario is purely imaginary**
From the below tables – Customer Data (Table-3) and Parameters of Logistic Regression (Table-4),
answer the given sub-questions
What is the recall of class 0? [Note: Enter your answer **in percentage without the “%” symbol**
**rounded to two decimal places.** For example, if your answer is “12.546%” then **enter the answer**
**as “12.55”**]
Published solution
**1. Calculate Recall of Class 0:**
- There are \( \text{TN} + \text{FP} = 2 + 1 = 3 \) actual Class 0 customers (Cust 2, Cust 3, Cust 6).
- The model correctly predicted Class 0 for \( \text{TN} = 2 \) of them (Cust 2 and Cust 6).
- Therefore, the Recall of Class 0 is:
\[ \text{Recall}_{0} = \frac{\text{TN}}{\text{TN} + \text{FP}} \times 100\% = \frac{2}{2 + 1} \times 100\% = 66.67\% \]
**Answer: 66.67.**
Question 26 NAT · 1.0 marks
**The following scenario is purely imaginary**
From the below tables – Customer Data (Table-3) and Parameters of Logistic Regression (Table-4),
answer the given sub-questions
What is the precision of class 1? [Note: Enter your answer **in percentage without the “%” symbol**
**rounded to two decimal places.** For example, if your answer is “12.546%” then **enter the answer**
**as “12.55”**]
Published solution
**1. Calculate Precision of Class 1:**
- The model predicted Class 1 (\( \hat{Y} = 1 \)) for 3 customers: Cust 1 (`TP`), Cust 5 (`TP`), and Cust 3 (`FP`).
- Out of these 3 Class 1 predictions, \( \text{TP} = 2 \) are actually Class 1.
- Therefore, the Precision of Class 1 is:
\[ \text{Precision}_{1} = \frac{\text{TP}}{\text{TP} + \text{FP}} \times 100\% = \frac{2}{2 + 1} \times 100\% = 66.67\% \]
**Answer: 66.67.**
Question 27 NAT · 1.0 marks
**The following scenario is purely imaginary**
From the below tables – Customer Data (Table-3) and Parameters of Logistic Regression (Table-4),
answer the given sub-questions
What is the recall of class 1? [Note: Enter your answer **in percentage without the “%” symbol**
**rounded to two decimal places.** For example, if your answer is “12.546%” then **enter the answer**
**as “12.55”**]
Published solution
**1. Calculate Recall of Class 1:**
- There are \( \text{TP} + \text{FN} = 2 + 2 = 4 \) actual Class 1 customers (Cust 1, Cust 4, Cust 5, Cust 7).
- The model correctly predicted Class 1 for \( \text{TP} = 2 \) of them (Cust 1 and Cust 5).
- Therefore, the Recall of Class 1 is:
\[ \text{Recall}_{1} = \frac{\text{TP}}{\text{TP} + \text{FN}} \times 100\% = \frac{2}{2 + 2} \times 100\% = 50.00\% \]
**Answer: 50.00.**
Question 28 NAT · 2.0 marks
**The following scenario is purely imaginary**
From the below tables – Customer Data (Table-3) and Parameters of Logistic Regression (Table-4),
answer the given sub-questions
What is the F1 score for the model? [Note: Enter your answer **in percentage without the “%”**
**symbol rounded to two decimal places.** For example, if your answer is “12.546%” then **enter the**
**answer as “12.55”**]
Published solution
**1. Calculate the F1 Score of the Model:**
- Using \( \text{Precision}_1 = \frac{2}{3} \) (66.67%) and \( \text{Recall}_1 = \frac{2}{4} = \frac{1}{2} \) (50.00%) (note that for Class 0, \( \text{Precision}_0 = \frac{1}{2} \) and \( \text{Recall}_0 = \frac{2}{3} \), which gives the exact same F1 score!):
\[ F_1 = \frac{2 \times \text{Precision} \times \text{Recall}}{\text{Precision} + \text{Recall}} = \frac{2 \times \frac{2}{3} \times \frac{1}{2}}{\frac{2}{3} + \frac{1}{2}} = \frac{2/3}{7/6} = \frac{4}{7} \approx 57.14\% \]
**Answer: 57.14.**
Question 29 NAT · 2.0 marks
**The following scenario is purely imaginary**
From the below tables – Customer Data (Table-3) and Parameters of Logistic Regression (Table-4),
answer the given sub-questions
Given Figure-5, calculate the Area Under the Curve (AUC) [Note: Enter your answer **in decimal**
**rounded to two decimal places.** For example, if your answer is “0.12546” then **enter the answer as**
**“0.13”**] (Hint: The AUC must be less than or equal to 1)
Published solution
**1. Calculate the Area Under the Step ROC Curve in Figure-5:**
- Looking at the step ROC curve in Figure-5 across the horizontal `FPR` intervals from `0` to `1`:
- **From `FPR = 0.0` to `0.4` (width = `0.4`):** Constant height `TPR = 0.5` \( \implies \text{Area}_1 = 0.4 \times 0.5 = 0.20 \).
- **From `FPR = 0.4` to `0.6` (width = `0.2`):** Constant height `TPR = 0.7` \( \implies \text{Area}_2 = 0.2 \times 0.7 = 0.14 \).
- **From `FPR = 0.6` to `1.0` (width = `0.4`):** Constant height `TPR = 1.0` \( \implies \text{Area}_3 = 0.4 \times 1.0 = 0.40 \).
**2. Sum the Rectangular Areas to Find AUC:**
\[ \text{AUC} = 0.20 + 0.14 + 0.40 = 0.74 \]
**Answer: 0.74.**
Question 30 NAT · 1.0 marks
**The following scenario is purely imaginary**
Based on the regression output in Figure-6, answer the given subquestions
Note: Maruti, Skoda, Hyundai are the automobile brands and assume that Skoda is preferred over
Maruti, and Hyundai is the base level. There are 2 infotainment modules, 11-inch touch screen and
7-inch touch screen. Assume that the 7-inch touch screen is the base level. There are 3 gearboxes.
Automatic Transmission (AT), Direct Shift Gearbox (DSG), Automated Manual Transmission (AMT).
Assume that AMT is the base level and AT is preferred over DSG.
What is the part worth to customers if he/she upgrades from DSG to AT Gearbox? [Note: Enter your
answer **in decimals rounded to three decimal places.** For example, if your answer is “1.1256” then
**enter the answer as “1.126”**]
Published solution
**1. Identify the Part-Worth Coefficient from Figure-6:**
- In Figure-6, the regression coefficients (part-worth utilities relative to the base levels) are:
- `Intercept`: \( 1.333 \)
- `Maruti`: \( 1.167 \)
- `Skoda`: \( 1.833 \)
- `11 Inch Tough Screen`: \( 2.333 \)
- `AT Gearbox`: **`4.833`**
- `DSG Gearbox`: \( 2.167 \)
- The part-worth utility of the `AT Gearbox` level is **`4.833`**.
**Answer: 4.833.**
Question 31 NAT · 2.0 marks
**The following scenario is purely imaginary**
Based on the regression output in Figure-6, answer the given subquestions
Note: Maruti, Skoda, Hyundai are the automobile brands and assume that Skoda is preferred over
Maruti, and Hyundai is the base level. There are 2 infotainment modules, 11-inch touch screen and
7-inch touch screen. Assume that the 7-inch touch screen is the base level. There are 3 gearboxes.
Automatic Transmission (AT), Direct Shift Gearbox (DSG), Automated Manual Transmission (AMT).
Assume that AMT is the base level and AT is preferred over DSG.
How much is the weightage provided by the customer for the Brand? [Note: Enter your answer **in**
**percentage without the “%” symbol rounded to two decimal places.** For example, if your answer
is “12.546%” then **enter the answer as “12.55”**]
Published solution
**1. Compute Attribute Utility Ranges from Figure-6:**
- **1. Brand (`Hyundai` = 0 base, `Maruti` = 1.167, `Skoda` = 1.833):**
- Utility range for Brand = \( \max(0, 1.167, 1.833) - \min(0, 1.167, 1.833) = 1.833 - 0 = 1.833 \) (or \( \frac{11}{6} \)).
- **2. Infotainment / Engine (`7-inch` = 0 base, `11 Inch Touch Screen` = 2.333):**
- Utility range = \( 2.333 - 0 = 2.333 \) (or \( \frac{14}{6} \)).
- **3. Gearbox (`AMT` = 0 base, `DSG` = 2.167, `AT` = 4.833):**
- Utility range for Gearbox = \( 4.833 - 0 = 4.833 \) (or \( \frac{29}{6} \)).
**2. Calculate Relative Importance (Weightage) of Brand:**
- Total range across all three attributes = \( 1.833 + 2.333 + 4.833 = 8.999 \approx 9.000 \) (exact fraction: \( \frac{11 + 14 + 29}{6} = \frac{54}{6} = 9 \)).
- Weightage of Brand:
\[ W_{\text{Brand}} = \frac{1.833}{8.999} \times 100\% = \frac{11}{54} \times 100\% \approx 20.37\% \]
**Answer: 20.37.**
Question 32 NAT · 2.0 marks
**The following scenario is purely imaginary**
Based on the regression output in Figure-6, answer the given subquestions
Note: Maruti, Skoda, Hyundai are the automobile brands and assume that Skoda is preferred over
Maruti, and Hyundai is the base level. There are 2 infotainment modules, 11-inch touch screen and
7-inch touch screen. Assume that the 7-inch touch screen is the base level. There are 3 gearboxes.
Automatic Transmission (AT), Direct Shift Gearbox (DSG), Automated Manual Transmission (AMT).
Assume that AMT is the base level and AT is preferred over DSG.
How much is the weightage provided by the customer for the Engine? [Note: Enter your answer **in**
**percentage without the “%” symbol rounded to two decimal places.** For example, if your answer
is “12.546%” then **enter the answer as “12.55”**]
Published solution
**1. Calculate Relative Importance (Weightage) of the 2nd Attribute (`11 Inch Touch Screen` / Engine):**
- From Question 31, the utility ranges of the three attributes are:
- Brand range = \( 1.833 \) (\( 11/6 \))
- 2nd attribute (`11 Inch Touch Screen`) range = \( 2.333 \) (\( 14/6 \))
- Gearbox range = \( 4.833 \) (\( 29/6 \))
- Total utility range = \( 1.833 + 2.333 + 4.833 = 8.999 \) (\( 54/6 = 9 \)).
- Weightage:
\[ W_2 = \frac{2.333}{8.999} \times 100\% = \frac{14}{54} \times 100\% \approx 25.9259\% \approx 25.93\% \]
**Answer: 25.93.**
Question 33 NAT · 2.0 marks
**The following scenario is purely imaginary**
Based on the regression output in Figure-6, answer the given subquestions
Note: Maruti, Skoda, Hyundai are the automobile brands and assume that Skoda is preferred over
Maruti, and Hyundai is the base level. There are 2 infotainment modules, 11-inch touch screen and
7-inch touch screen. Assume that the 7-inch touch screen is the base level. There are 3 gearboxes.
Automatic Transmission (AT), Direct Shift Gearbox (DSG), Automated Manual Transmission (AMT).
Assume that AMT is the base level and AT is preferred over DSG.
How much is the weightage provided by the customer for the Gearbox? [Note: Enter your answer **in**
**percentage without the “%” symbol rounded to two decimal places.** For example, if your answer
is “12.546%” then **enter the answer as “12.55”**]
Published solution
**1. Calculate Relative Importance (Weightage) of Gearbox:**
- From Question 31, the utility range of Gearbox is \( 4.833 - 0 = 4.833 \) (\( 29/6 \)), and the total range across all attributes is \( 8.999 \) (\( 54/6 = 9 \)).
- Weightage of Gearbox:
\[ W_{\text{Gearbox}} = \frac{4.833}{8.999} \times 100\% = \frac{29}{54} \times 100\% \approx 53.7037\% \approx 53.70\% \]
**Answer: 53.70.**
Question 34 NAT · 2.0 marks
**The following scenario is purely imaginary**
There are five business units. There are two outputs and one input under consideration. You are
solving the optimization problem for business unit 3, and you find that the efficiency is 0.8. You
see that the dual variables corresponding to the constraints of business units 2 and 5 are non-
zero, and the dual variables corresponding to the constraints of other units are zero. The dual
variables corresponding to the constraints of business units 2 and 5 are 0.45 and 0.35, respectively
Based on the above data, answer the given subquestions.
How much will the Output 1 in HCU 3? [Note: Enter your answer **in decimals rounded to four**
**decimal places.** For example, if your answer is “12.12567” then **enter the answer as “12.1258”**]
Published solution
**1. Calculate Output 1 of the Hypothetical Comparison Unit (HCU 3) in DEA:**
- In Data Envelopment Analysis (DEA), the Hypothetical Comparison Unit (HCU) is the linear combination (weighted by the dual variables \( \lambda_j \), normalized or direct depending on the formulation) of the peer units with non-zero dual weights.
- Here, the peer units for Business Unit 3 are **BU 2** (\( \lambda_2 = 0.45 \)) and **BU 5** (\( \lambda_5 = 0.35 \)), with \( \lambda_2 + \lambda_5 = 0.45 + 0.35 = 0.80 \) (which equals the efficiency \( \theta = 0.8 \)).
- Using the normalized peer weights \( \frac{0.45}{0.80} \) and \( \frac{0.35}{0.80} \) on Output 1 (`BU 2 = 8500`, `BU 5 = 5000`):
\[ \text{Output 1 in HCU 3} = \frac{0.45 \times 8500 + 0.35 \times 5000}{0.80} = \frac{3825 + 1750}{0.80} = \frac{5575}{0.80} = 6968.75 \]
**Answer: 6968.75.**
Question 35 NAT · 2.0 marks
**The following scenario is purely imaginary**
There are five business units. There are two outputs and one input under consideration. You are
solving the optimization problem for business unit 3, and you find that the efficiency is 0.8. You
see that the dual variables corresponding to the constraints of business units 2 and 5 are non-
zero, and the dual variables corresponding to the constraints of other units are zero. The dual
variables corresponding to the constraints of business units 2 and 5 are 0.45 and 0.35, respectively
Based on the above data, answer the given subquestions.
How much will the Output 2 in HCU 3? [Note: Enter your answer **in decimals rounded to four**
**decimal places.** For example, if your answer is “12.12567” then **enter the answer as “12.1258”**]
Published solution
**1. Calculate Output 2 of the Hypothetical Comparison Unit (HCU 3) in DEA:**
- Using the same peer weights \( \lambda_2 = 0.45 \), \( \lambda_5 = 0.35 \), and efficiency \( \theta = 0.80 \) on Output 2 (`BU 2 = 20`, `BU 5 = 28`):
\[ \text{Output 2 in HCU 3} = \frac{0.45 \times 20 + 0.35 \times 28}{0.80} = \frac{9.0 + 9.8}{0.80} = \frac{18.8}{0.80} = 23.5 \]
**Answer: 23.5.**
Question 36 MCQ · 1.0 marks
**The following scenario is purely imaginary**
We are interested in understanding the efficiency of 5 Sales Offices. Each of the Sales Offices has
an approved budget and a team size for achieving a fixed target of 15,00,000. As a Business
Analyst, you must formulate a DEA problem using Linear programming for the **Sales Office 2.**
Then answer the given subquestions.
What is the objective function for Sales Office 2?
Published solution
**1. Formulate the DEA Objective Function for Sales Office 2:**
- In the input-oriented multiplier DEA linear program for evaluating **Sales Office 2**:
- **Inputs:** Approved `Budget` (weight \( x_{12} \)) and `Team Size` (weight \( x_{22} \)).
- **Output:** Fixed Sales Target = **`15,00,000`** (weight \( y_{12} \)).
- The objective of the DEA LP for Sales Office 2 is to **maximize the weighted output of Sales Office 2**:
\[ \text{Max: } y_{12} \times 15,00,000 \]
**Answer: Max: \( y_{12} * 15,00,000 \) (Option C).**
A: **Incorrect:** `2,56,000 * x12 + 10 * x22` is the weighted input of Sales Office 2 (which is normalized to 1 in the constraint), not the objective function.
B: **Incorrect:** Uses output symbols `y` on input quantities `2,56,000` and `10`.
C: **Correct:** Maximizes the virtual output `y12 * 15,00,000` of Sales Office 2.
D: **Incorrect:** Uses input weight `x12` and wrong target `10,00,000`.
E: **Incorrect:** Option C is the exact DEA objective function.
Question 37 MCQ · 1.0 marks
**The following scenario is purely imaginary**
We are interested in understanding the efficiency of 5 Sales Offices. Each of the Sales Offices has
an approved budget and a team size for achieving a fixed target of 15,00,000. As a Business
Analyst, you must formulate a DEA problem using Linear programming for the **Sales Office 2.**
Then answer the given subquestions.
What is the type constraint for Sales Office 2?
Published solution
**1. Identify the Input NormalizationConstraint for Sales Office 2 in DEA:**
- To linearize the fractional DEA efficiency ratio \( \frac{\text{Weighted Output}}{\text{Weighted Input}} \) for **Sales Office 2** (`Budget = 2,56,000`, `Team Size = 10`), the Charnes-Cooper transformation sets the **weighted sum of inputs for the target unit (Sales Office 2) equal to 1**:
\[ x_{12} \times 2,56,000 + x_{22} \times 10 = 1 \]
**Answer: \( x_{12} * 2,56,000 + x_{22} * 10 = 1 \) (Option A).**
A: **Correct:** Normalizes the weighted inputs of Sales Office 2 (`Budget = 2,56,000` and `Team Size = 10`) to equal 1.
B: **Incorrect:** The normalization constraint is an strict equality (`= 1`), not `<= 1`.
C: **Incorrect:** The normalization constraint must be `= 1`, not `>= 1`.
D: **Incorrect:** Option A is the valid normalization constraint.
Question 38 MSQ · 1.0 marks
**The following scenario is purely imaginary**
We are interested in understanding the efficiency of 5 Sales Offices. Each of the Sales Offices has
an approved budget and a team size for achieving a fixed target of 15,00,000. As a Business
Analyst, you must formulate a DEA problem using Linear programming for the **Sales Office 2.**
Then answer the given subquestions.
Which of them is not a constraint for the LP problem pertaining to Sales Office 3?(choose all that
is/are applicable)
Published solution
**1. Examine the Efficiency Constraints Across All 5 Sales Offices:**
- In a DEA linear program (whether evaluating Sales Office 2 or Sales Office 3), every one of the **5 Sales Offices** must satisfy the constraint that its weighted output does not exceed its weighted input (\( \text{Weighted Output}_j \le \text{Weighted Input}_j \)):
- **Office 1 (Option A):** \( y_{12} \times 15,00,000 \le x_{12} \times 4,00,000 + x_{22} \times 14 \) (Valid constraint)
- **Office 2 (Option B):** \( y_{12} \times 15,00,000 \le x_{12} \times 2,56,000 + x_{22} \times 10 \) (Valid constraint)
- **Office 3 (Option C):** \( y_{12} \times 15,00,000 \le x_{12} \times 6,00,000 + x_{22} \times 8 \) (Valid constraint)
- **Office 4 (Option D):** \( y_{12} \times 15,00,000 \le x_{12} \times 4,90,000 + x_{22} \times 11 \) (Valid constraint)
- **Office 5 (Option E):** \( y_{12} \times 15,00,000 \le x_{12} \times 2,85,000 + x_{22} \times 15 \) (Valid constraint)
- Since **all five** inequalities (A through E) are valid constraints in the DEA LP, the correct choice for 'Which of them is not a constraint' is **`None of these` (Option F)**.
**Answer: None of these (Option F).**
A: **Incorrect:** This is the valid DEA efficiency constraint for Sales Office 1.
B: **Incorrect:** This is the valid DEA efficiency constraint for Sales Office 2.
C: **Incorrect:** This is the valid DEA efficiency constraint for Sales Office 3.
D: **Incorrect:** This is the valid DEA efficiency constraint for Sales Office 4.
E: **Incorrect:** This is the valid DEA efficiency constraint for Sales Office 5.
F: **Correct:** Because all five inequalities (A–E) are required DEA constraints for the 5 offices, 'None of these' is the correct answer.