Question

Assume that when adults with smartphones are randomly​ selected, 42% use them in meetings or classes. If 5 adult smartphone users are randomly​ selected, find the probability that at least 2 of them use their smartphones in meetings or classes. The probability is _

Answer 1

P(using smartphone in meetings or classes), p = 0.42

q = 1 - 0.42 = 0.58

Sample size, n = 5

Binomial distribution: P(X) = nCx p^x q^n-x

P(at least 2) = 1 - P(X < 2)

= 1 - P(0) + P(1)

= 1 - 0.58⁵ - 5x0.42x0.58⁴

= 0.6967