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 exactly 4 of them use their smartphones in meetings or classes. The probability is

Answer 1

Answer:

≈ 0.2526

Step-by-step explanation:

The number of combinations of 4 out of 8:

• 8C4 = 8!/(4!(8-4)!)= 8*7*6*5/(1*2*3*4)= 70

Success factor is:

• 57% = 0.57

and failure factor is:

• (100 - 57)%= 43%= 0.43

Probability:

• 0.57⁴*0.43⁴*70 ≈ 0.2526