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 exactly 2 of them use their smartphones in meetings or classes

Answer 1

Answer:

The probability that exactly 2 of 5 use their smartphones in meetings or classes is 0.3442.

Step-by-step explanation:

Let X = number of adults who use smartphones in meetings or classes.

The probability of the random variable X is, P(X) = p = 0.42

A sample of n = 5 adult smartphone users are selected.

The random variable X follows a Binomial distribution with parameters n and p.

The probability mass function of X is:

$P(X=x)={n\choose x}p^{x}(1-p)^{n-x};\ x=0,1,2,3...$

Compute the value of P (X = 2) as follows:

$P(X=2)={5\choose 2}0.42^{2}(1-0.42)^{5-2}\\=10\times 0.1764\times0.195112\\=0.344177\\\approx0.3442$

Thus, the probability that exactly 2 of 5 use their smartphones in meetings or classes is 0.3442.