Question

Assume that when adults with smartphones are randomly​ selected, 63​% use them in meetings or classes. If adult smartphone users are randomly​ selected, find the probability that exactly of them use their smartphones in meetings or classes.

Answer 1

Solved using binomial, probability = 5.7%

Explanation:

Number of people (N) = 7

Probability of success (using phone) = 63% = 0.63

So, probability of failure (not using phone) = 1 - 0.63 = 37

Number of success (r) = 2

N c r . P^r . Q^n-r

7 c 2 (0.63)^2 (0.37)^5

= 21 (0.3969) (0.0069)

= 0.057