Question

Select the correct answer.
A bookstore rents books to students for $2 per book. The cost per hour of running the bookstore is $300. The numbers of books and the probabilities that the bookstore would rent them in an hour mimics the distribution of the outcomes of flipping four coins. The number of books rented was observed to be the same as the number of heads that appear in a four-coin flip. This distribution is represented in the table.

No. of Heads Probability
0

1

2

3


4


Given the data in the table, what is the expected number of books rented in one hour?

A.
1

B.
2

C.
3

D.
4

Answer 1

B. 2

Reason: The number rented follows Binomial(4, 0.5). Expected value = 4 * 0.5 = 2.