Question

Suppose 40% of all college students have a computer at home and a sample of 64 is taken. What is the probability that more than 30 of those in the sample have a computer at home? 0.3686 0.1314 0.8686 0.6314 0.1343

Answer 1

0.13093

Explanation:

Give. That :

Population mean = 40% = 0.4

Sample size (n) = 64

Probability that more than 30 have computer at home

Mean = np = 64 * 0.4 = 25.6

Standard deviation = sqrt(n*p*(1-p)) = 3.919

P(x > 30)

USing the relation to obtain the standardized score (Z) :

Z = (x - m) / s

Z = (30 - 25.6) / 3.919 = 1.1227353

p(Z < 1.122) = 0.13093 ( Z probability calculator)