
Statistics for Data Science II End Term: 13 April 2025, Set QDF1 (January 2025 term)
The IIT Madras BS Statistics for Data Science II (Stats 2) End Term paper sat on 13 Apr 2025, in the January 2025 term, set QDF1: 17 questions for 40 marks in 180 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.
- 17
- 40
- 180 min
- 8
- 1
- 8
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Correct answer
Question 2
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Question 3
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Question 4
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Correct answer: 21.65 (accepted within ±0.03)
Question 5
A software company is analyzing the bug reports for their newly developed application. Some bug reports identify a critical bug in the application. To estimate the probability p of a bug report identifying a critical bug, they collect a random sample of 200 bug reports, and find that 50 are classified as critical. The company adopts a Bayesian approach with a Beta distribution as the prior for p.
Based on the above data, answer the given subquestions.
The company assumes a Beta(1.4, b) prior for p. Given that prior knowledge suggests the expected value of p is approximately 0.2, determine the appropriate value of b.
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Correct answer
Question 6
A software company is analyzing the bug reports for their newly developed application. Some bug reports identify a critical bug in the application. To estimate the probability p of a bug report identifying a critical bug, they collect a random sample of 200 bug reports, and find that 50 are classified as critical. The company adopts a Bayesian approach with a Beta distribution as the prior for p.
Based on the above data, answer the given subquestions.
Using the prior distribution and the observed data, compute the posterior distribution of p.
Beta(50.4, 154.6)
Beta(1.4, 5.6)
Beta(5.6, 1.4)
Beta(51.4, 155.6)
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Correct answer
Beta(51.4, 155.6)
Question 7
Based on the above data, answer the given subquestions.
Find the method of moments estimate of θ for the given sample.
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Correct answer: 4
Question 8
Based on the above data, answer the given subquestions.
The company has a policy requirement that the average waiting time must not exceed 3 minutes. Based on the estimated value of θ, determine whether the company meets this requirement.
The company meets the requirement.
The company does not meet the requirement.
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Correct answer
The company meets the requirement.
Question 9
A research team is analyzing customer complaints per day for a new service. The number of complaints X follows a Poisson distribution with an unknown average rate λ. The number of complaints observed over a period of 10 days are as follows :
3, 5, 2, 4, 6, 3, 4, 7, 5, 4
The team aims to estimate λ using two different methods: Maximum Likelihood Estimation (MLE) and Bayesian Estimation.
Based on the above data, answer the given subquestions.
Find the maximum likelihood estimate of λ for the given sample. Enter the answer correct to one decimal place.
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Correct answer: 4.3 (accepted within ±0.2)
Question 10
A research team is analyzing customer complaints per day for a new service. The number of complaints X follows a Poisson distribution with an unknown average rate λ. The number of complaints observed over a period of 10 days are as follows :
3, 5, 2, 4, 6, 3, 4, 7, 5, 4
The team aims to estimate λ using two different methods: Maximum Likelihood Estimation (MLE) and Bayesian Estimation.
Based on the above data, answer the given subquestions.
Assume the prior distribution of λ to be Gamma(3, 2). Determine the posterior distribution of λ.
Gamma(45, 12)
Gamma(12, 46)
Gamma(46, 12)
Gamma(12, 45)
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Correct answer
Gamma(46, 12)
Question 11
Based on the above data, answer the given subquestions.
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Correct answer: 0.09 (accepted within ±0.03)
Question 12
Based on the above data, answer the given subquestions.
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Correct answer: 0.975 (accepted within ±0.025)
Question 13
Based on the above data, answer the given subquestions.
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Correct answer: 6
Question 14
Based on the above data, answer the given subquestions.
16
18.8
6
2.8
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Correct answer
2.8
Question 15
Based on the above data, answer the given subquestions.
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Correct answer: 3
Question 16
Based on the above data, answer the given subquestions.
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Correct answer
Question 17
Based on the above data, answer the given subquestions.
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Correct answer: 0.117 (accepted within ±0.003)