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May 2021 term · Statistics for Data Science II · BSMA1004

Stats 2 Quiz 1: 11 July 2021, Set POD21QZBQPA (May 2021 term)

The IIT Madras BS Statistics for Data Science II (Stats 2) Quiz 1 paper sat on 11 Jul 2021, in the May 2021 term, set POD21QZBQPA: 19 questions for 25 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.

Questions
19
Marks
25
Duration
120 min
MCQ
12
Numerical
7

Updated

Official paper: IIT M QUIZ EXAM POD21QZBQPB AN 11 July 2021 · No negative marking.

Question 1

+0.5 marksOne correct option

Use the following information to answer the given subquestions.
Consider 4 bits, where each bit can be either 0 or 1, transmitted over a noisy channel, i.e., there is a possibility of error. The probability of 1 bit getting changed is p, independent of all other bits. Let the random variable X denote the number of bits that changed.

Identify the distribution of X.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • B

Question 2

+1 markOne correct option

Use the following information to answer the given subquestions.
Consider 4 bits, where each bit can be either 0 or 1, transmitted over a noisy channel, i.e., there is a possibility of error. The probability of 1 bit getting changed is p, independent of all other bits. Let the random variable X denote the number of bits that changed.

Suppose the number of errors in 5 transmissions are x1 = 0, x2 = 1, x3 = 0, x4 = 2, x5 = 0: What is the likelihood function of p?

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • D

Question 3

+1.5 marksNumerical answer

Use the following information to answer the given subquestions.
Consider 4 bits, where each bit can be either 0 or 1, transmitted over a noisy channel, i.e., there is a possibility of error. The probability of 1 bit getting changed is p, independent of all other bits. Let the random variable X denote the number of bits that changed.

Suppose the number of errors in 5 transmissions are x1 = 0, x2 = 1, x3 = 0, x4 = 2, x5 = 0: Find the Maximum likelihood estimate for p. Enter the answer correct to two decimal places.

Show answer

Correct answer: 0.15

Question 4

+1 markOne correct option

Based on the above data, answer the given subquestions.

Calculate the first moment of X.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • B

Question 5

+0.5 marksNumerical answer

Based on the above data, answer the given subquestions.

Show answer

Correct answer: 1.8

Question 6

+1.5 marksNumerical answer

Based on the above data, answer the given subquestions.

Show answer

Correct answer: 0.4

Question 7

+1.5 marksOne correct option

Based on the above data, answer the given subquestions.

Find the likelihood function for the given sample.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • C

Question 8

+1.5 marksNumerical answer

Based on the above data, answer the given subquestions.

NOTE: Enter your answer to the nearest integer.

Show answer

Correct answer: 3

Question 9

+1.5 marksOne correct option

Based on the above data, answer the given subquestions.

Are X and Y independent?

  1. A

    Yes

  2. B

    No

Show answer

Correct answer

  • A

    Yes

Question 10

+1.5 marksNumerical answer

Based on the above data, answer the given subquestions.

Find the value of P(X > Y). Write your answer correct to two decimal places.

Show answer

Correct answer: 0.55 (accepted within ±0.03)

Question 11

+1.5 marksOne correct option
  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • D

Question 12

+1.5 marksOne correct option

A random sample of size 300 is collected from a population with a standard deviation of 20. Find a lower bound on the probability that the sample mean will be at most 4 away from the actual mean using the weak law of large numbers.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • B

Question 13

+1 markNumerical answer

Use the following information to answer the given subquestions.

Show answer

Correct answer: 1.33 (accepted within ±0.03)

Question 14

+1.5 marksOne correct option

Use the following information to answer the given subquestions.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • D

Question 15

+1 markNumerical answer

Use the following information to answer the given subquestions.

Show answer

Correct answer: 0.625 (accepted within ±0.025)

Question 16

+2 marksOne correct option
  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • D

Question 17

+2 marksOne correct option
  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • C

Question 18

+1 markOne correct option

Based on the above data, answer the given subquestions.

Find the moment generating function of X.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • B

Question 19

+1.5 marksOne correct option

Based on the above data, answer the given subquestions.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • D