Chapter 2.4, Problem 9E

Suppose that the percentage of American drivers who multitask (e.g., talk on cell phones. eat a snack, or text at the same time they are driving) is approximately 80%. In a random sample of $n=20$ drivers, let X equal the number of multitaskers.

(a) How is X distributed?

(b) Give the values of the mean, variance, and standard deviation of X.

(c) Find (1) $P\left(X=15\right)$, (ii) $P\left(X>15\right)$, and (iii) $P\left(X<15\right)$.