STA301 Statistics and Probability Quiz No.2 2024

Q1: In a standard normal distribution, which of the following is true?

A) P(Z > 2.0) = 0.9772

B) P(Z < -2.0) = 0.0228

C) P(-2.0 < Z < 2.0) = 0.9544

D) P(Z = 2.0) = 0.0228

Q2: The correlation coefficient:

A) makes the scatterplot redundant.

B) should be interpreted alongside the relevant scatterplot.

C) can be expressed as a percentage.

D) all of these.

Q3: If, in a binomial distribution, ‘p’ is less than 0.5, the distribution will be:

A) symmetrical.

B) leptokurtic.

C) skewed to right.

D) skewed to left.

Q4: If X and Y are independent random variables, then E(XY) is equal to:

A) E(X) + E(Y)

B) E(X)E(Y)

C) E(X) – E(Y)

D) [E(X)]2

Q5: If, in a Poisson process, on average, 4 calls are received per minute, then the set of possible values for the number of calls received in a 15-second interval is:

A) 0, 1, 2

B) 3, 4, 5, …

C) 0, 1

D) 0, 1, 2, 3

Q6: The mean of a binomial distribution is equal to:

A) npq

B) p

C) npq

D) np

Q7: The mean of the probability distribution of a random variable X is technically known as:

A) Variance of X

B) Standard deviation of X

C) Mean

D) None of these

Q8: If the second moment-ratio of a distribution is 2.144, then the distribution is:

A) leptokurtic.

B) mesokurtic.

C) Flatter than normal distribution

D) more peaked than the normal distribution.

Q9: The mean and standard deviation of the standard normal distribution are:

A) 1 and 0 respectively

B) 0 and 2 respectively

C) 0 and 1 respectively

D) 1 and 1 respectively

Q10: If X and Y are two random variables with the following joint p.d.f, then X and Y are:

A) Dependent

B) Independent

C) Positively correlated

D) Negatively correlated