Question

Assume that when adults with smartphones are randomly​ selected, 54​% use them in meetings or classes. If 5 adult smartphone users are randomly​ selected, find the probability that at least 2 of them use their smartphones in meetings or classes.

The probability is nothing. ​(Round to four decimal places as​ needed.)

Answer 1

Solution :

Given that ,

p = 0.54

1 - p = 1 - 0.54 = 0.46  

n = 5

x 2

Using binomial probability formula ,

P(X = x) = ((n! / (n - x)!) * p^x * (1 - p)^{n - x}

p (  x   2 )  = p (x = 2 )+ p (x = 3) + p (x = 4) +  p (x = 5 )  

  = (5 / (5 - 2)!) * 0.54² * 0.46)^{3 +}

= (5! / (5 - 3)!) * 0.54³ * 0.46)² +

  = (5 ! / (5 - 4)!) * 0.54⁴ * 0.46)¹  +

   = (5! / ( 5 - 5)!) * 0.54⁵ * 0.46)⁰ +

p (  x 2 )  = 0.8585

Probability = 0.8585