Question

Assume that when adults with smartphones are randomly​ selected, 57​% use them in meetings or classes. If 8 adult smartphone users are randomly​ selected, find the probability that at least 6

of them use their smartphones in meetings or classes.

The probability is___?

​(Round to four decimal places as​ needed.)

Answer 1

Probability that adults use smartphones in meetings or classes = 0.57

8 adult smartphones are randomly selected.

Thus n = 8

From binomial probability distribution, Probability of x successes out of n is given by

Where p is the probability of a success

Here, n = 8, p = 0.57.

P(at least 6) = P(6 successes) + P(7 successes) + P(8 successes)

P(6 successes) = = 0.17756

P(7 successes) = = 0.06725

P(8 successes) = = 0.011143

P(at least 6) = 0.17756 + 0.06725 + 0.011143 = 0.255953