Use the following information for questions:
Suppose that a student needs to buy 6 books for her history course. The number of books that she will be able to find used is a binomial random variable X with n = 6 and p = 0.30. In other words, the probability that she will find any given book used is 0.30, and is independent from one book to the next.
-What is the expected number of used books she will find, E(X)?
A) 1.8
B) 2.0
C) 3.0
D) 6..0

Question

Use the following information for questions:
 Suppose that a student needs to buy 6 books for her history course. The number of books that she will be able to find used is a binomial random variable X with n = 6 and p = 0.30. In other words, the probability that she will find any given book used is 0.30, and is independent from one book to the next.
-What is the expected number of used books she will find, E(X)?
A) 1.8
B) 2.0
C) 3.0
D) 6..0

Quizplus · Accepted Answer

The expected value E(X) of a binomial distribution is calculated as n*p, where n is the number of trials and p is the probability of success on each trial. Here, n = 6 and p = 0.30, so E(X) = 6 * 0.30 = 1.8.

Use the Following Information for Questions