
Statistics for Data Science II Quiz 2: 4 August 2024 (May 2024 term)
The IIT Madras BS Statistics for Data Science II (Stats 2) Quiz 2 paper sat on 4 Aug 2024, in the May 2024 term: 16 questions for 40 marks in 120 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.
- 16
- 40
- 120 min
- 8
- 7
- 1
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Question 2
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Question 3
A political survey is conducted to estimate the proportion of voters in a city who support a particular candidate. The true proportion of voters supporting the candidate is 0.45. A random sample of 500 voters is taken. Using Central limit theorem, what is the approximate probability that the sample proportion is between 0.43 and 0.47?
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Question 4
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Correct answer: 5
Question 5
Based on the above data answer the given subquestions.
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Correct answer: 0.11 (accepted within ±0.02)
Question 6
Based on the above data answer the given subquestions.
Which among the following options are true?
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Question 7
Based on the above data answer the given subquestions.
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Question 8
Based on the above data answer the given subquestions.
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Correct answer: 1
Question 9
A survey reports that the average time spent on social media per day by teenagers is 3 hours, with a standard deviation of 1 hour. A researcher selects a random sample of 64 teenagers. Based on the above data answer the given subquestions.
What is the expected value of the sample mean time spent on social media?
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Correct answer: 3
Question 10
A survey reports that the average time spent on social media per day by teenagers is 3 hours, with a standard deviation of 1 hour. A researcher selects a random sample of 64 teenagers. Based on the above data answer the given subquestions.
Using Chebyshev’s inequality, find the least upper bound on the probability that the sample mean time deviates from the population mean time by more than 0.5 hours.
0.0625
0.9375
0.031
0.015
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0.0625
Question 11
The recovery time for a particular surgery in a hospital follows an exponential distribution with a mean of 5 days. A researcher collects data from a sample of 49 patients.
Based on the above data answer the given subquestions.
Using CLT, what will be the approximate distribution of the sample mean recovery time?
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Question 12
The recovery time for a particular surgery in a hospital follows an exponential distribution with a mean of 5 days. A researcher collects data from a sample of 49 patients.
Based on the above data answer the given subquestions.
Using CLT, what is the approximate probability that the sample mean recovery time is between 4 and 6 days? Enter the answer correct to two decimal places.
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Correct answer: 0.84 (accepted within ±0.02)
Question 13
Based on the above data answer the given subquestions.
What is the distribution of X?
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Question 14
Based on the above data answer the given subquestions.
Find the conditional probability P(W = 1 | X = −1). Enter the answer correct to two decimal places.
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Correct answer: 0.12 (accepted within ±0.02)
Question 15
Based on the above data answer the given subquestions.
Find E[Y ]. Enter the answer correct to two decimal places.
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Correct answer: 0.66 (accepted within ±0.02)
Question 16
Based on the above data answer the given subquestions.
Find the probability density function of Y .
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