STA301 Quiz 3

Q1. Which of the following is correct property for joint probability distribution of X and Y:

1. None of the above
2. {f(Y,X)} = 1
3. {f(X,Y)} = 1
4. Both of the above

Correct answer: Both of the above

Q2. Given below is the probability distribution of random variable X. What is the value of “k” x 0 1 2

p(x) 0.70 k 0.10 0.07 0.03

A. 0.001

B. 0.10

C. 0.01 D. 0.03

Q3. Position of the normal curve changes along the horizontal axis due to:

1. Mean
2. Mode
3. Standard deviation
4. Median

Correct answer: Mean

Q4. The parameters of binomial distribution are:

1. n,p,q
2. p,q
3. n,p
4. n,(n-1)

Correct answer: n,p

Q5. The mean deviation of the normal distribution is approximately:

1. 7/8 of the S.D
2. 3/4 of the S.D
3. 1/2 of the S.D
4. 4/5 of the S.D

Correct answer: 4/5 of the S.D

Q6. Which one of the statement is true?

1. E (S2) = s2/n
2. E (S2) ≠ s2
3. E (s2) = б2
4. E (s2) = б2/n

Correct answer: E (s2) = б2

Q7. The marginal p.d.f. of __________ variables is obtained by integrating the other variable from the joint p.d.f.

1. Continuous
2. Qualitative
3. Binomial
4. Discrete

Correct answer: Continuous

Q8. In repeating sampling, which of the following possess desirable property of being Unbiased?

1. Sample proportion
2. Sample median
3. All of above
4. Sample Mean

Correct answer: All of above

Q9. Which of the following statements is correct?

1. A point estimate is an unbiased estimator if its standard deviation is the same as the actual value of the population standard deviation
2. All of the above statements are correct
3. A point estimate is an estimate of the range of a population parameter
4. A point estimate is a single value estimate of the value of a population parameter

Correct answer: A point estimate is a single value estimate of the value of a population parameter

Q10. Let X be a random variable with binomial distribution, that is (X=0,1,…, n). The expected value E[X] is

1. np
2. p
3. Xnp
4. np(1-p)

Correct answer: np