Question

Assume that when adults with smartphones are randomlyselected, 57...

Assume that when adults with smartphones are randomly​ selected, 57


57​% use them in meetings or classes. If 15


15 adult smartphone users are randomly​ selected, find the probability that fewer than 4


4 of them use their smartphones iThe probability is

nothing


.

​(Type an integer or decimal rounded to four decimal places as​ needed.)n meetings or classes.

Answer & Explanation
Verified Solved by verified expert

answer = 0.0040

Step-by-step explanation

here we use binomial probability distribution

P(x) = nCx *px*(1-p) n-x

we are given that p=0.57, n=15

hence

P(x < 4) =P(x=0) + P(x =1) + P(x=2) + P(x=3)

P(x=0) =15C0*0.570 (1-0.57)15-0 +15C1*0.571 (1-0.57)15-1 +15C2*0.572 (1-0.57)15-2 +15C3*0.573 (1-0.57)15-3

= 0.00000 + 0.00006 + 0.00059 + 0.00337

= 0.0040