This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: STA 4321/5325 - Spring 2010
Quiz 4 - February 19
There are ﬁve problems in this quiz. Each problem has exactly one correct answer.
Problem 1 A Bernoulli experiment has
(a) 1 outcome
(b) 2 outcomes
(c) 3 outcomes
(d) 4 outcomes
Problem 2 If X is a binomial random variable with parameters n and p (i.e., X is the number of
successes in n repetitions (independent) of a Bernoulli trial with success probability p), then
(a) E (X ) = n
(b) E (X ) = p
(c) E (X ) = p
n (d) E (X ) = np
Problem 3 Let X denote a random variable that has a binomial distribution with p =
n = 3. Then
(a) P (X = 1) = 1
2 (b) P (X = 1) = 1
8 (c) P (X = 1) = 3
8 (d) P (X = 1) = 1
4 1 1
2 and Problem 4 Let X be the number of failures before observing the ﬁrst success in successive
repetitions (independent) of a Bernoulli trial. Then
(a) X is a Bernoulli random variable.
(b) X is a binomial random variable.
(c) X − 1 is a geometric random variable.
(d) X is a geometric random variable.
Problem 5 If X is a geometric random variable with parameter p (i.e., the probability of success
of the associated Bernoulli trial is p), then
(a) P (X = 1) = 1 − p
(b) P (X = 1) = p
(c) P (X = 1) = (1 − p)p
(d) P (X = 1) = (1 − p)p2 2 ...
View Full Document