Answer in Statistics and Probability for Ellie #250652

Assume that one adult was smart phones are randomly selected 64% use them in meetings are classes if not adult smart phone users are randomly selected find the probability that exactly 2 of them use their smart phones in meetings or classes

p = 64 % = 0.64

Let 7 adult smartphone users are randomly selected,

n = 7

Then, the probability that exactly 2 of them use their smartphones in meetings or classes is

“P(X=x) = dfrac{n!}{x!(n-x)!} times p^x times (1-p)^{n-x} \ \nnp(X=2) = dfrac{7!}{2!(7-2)!} times 0.64^2 times (1-0.64)^{7-2} \ \nn= 21 times 0.64^2 times 0.36^5 \nn= 21times 0.4096times 0.00604\=0.052”