statistics - math

Question

Assume that when adults with smartphones are randomly​ selected,

56​%

use them in meetings or classes. If

11

adult smartphone users are randomly​ selected, find the probability that fewer than

55

of them use their smartphones in meetings or classes.

find probability ?

Answer 1

Use binomial probability.

Let X=# of adult smartphone users who uses them in meetings/classes

X ~ Binomial (n=11, p=0.56)

the calculate P(X<5) using some technology, like in https://stattrek.com/online-calculator/binomial.aspx.

Note that P(X<5) = P(X ≤ 4) = 0.15678132246