Question

assume that when adults with smartphones are randomly selected, 41% use them in meetings or classes. if 7 adult smartphone users are randomly selected, find the probability that atleast 5 of them use their smartphones in meetings kr classes

Answer 1

Let X be the number of adults uses smartphones in meetings or classes

As each smartphone user behaves independently ( trials are independent ) and probability of using smartphones in meetings or classes remains same for each person ( probability of success is constant)

X follow Binomial with n = 7 , p = 0.41

Probability mass function of X is

To find

= 0.0847 +0.0196 + 0.0019

= 0.1063

Probability that at least 5 of them use their smartphones in meetings or classes = 0.1063