Question

Assume that when adults with smartphones are randomly selected, 49% use them in meetings or classes. If 30 adult smartphone users are randomly selected, find the probability that exactly 23 of them use their smartphones

Answer 1

Answer: 0.0013684

Explanation:

Given the following :

Probability (p) = 49% = 0.49

Number of selected adults (n) = 30

Find the probability that exactly 23 use their smartphone.

The problem is abive can be solved using the binomial probability function.

Binomial probability :

P(X = x) = [n! / x! (n-x)!] * P^x * (1 - P)^(n-x)

At x = 23

P(X = 23) = [30! / 23! (30-23)!] * P^23 * (1-0.49)^(30-23)

P(X = 23) = [30! / 23! (7)!] * 0.49^23 * (0.51)^7

P(X =23) = (2035800) × 6.72203E−10

= 0.0013684