Question

Assume that when adults with smartphones are randomly​ selected, 47​% use them in meetings or classes. If 9 adult smartphone users are randomly​ selected, find the probability that exactly 7 of them use their smartphones in meetings or classes.

Answer 1

This is a binomial distribution with n=9, p=0.47.

$P(X=7)=C_9^70.47^7(1-0.47)^2=0.0512.$