Question

According to a recent study, the mean number of hours college students spent playing video games per month was 22 hours with a population standard deviation of 2 hours. Two weeks before final exams were scheduled to begin, 100 college students were randomly selected. What is the probability that the mean number of hours spent playing video games is less than 21.8 hours

Answer 1

ux=22

sdx=0.2

p(x<21.8)=0.159

just took the test

Explanation:

Answer 2

0.15866

Explanation:

Given that:

Mean, m = 22

Standard deviation, s = 2

Sample size, n = 100

P(x < 21.8):

Obtain the Zscore ;

Z = (x - m) ÷s/sqrt(n)

Z = (21.8 - 22) ÷ 2/sqrt(100)

Z = - 0. 2 ÷ 0.2

Z = - 1

P(Z < - 1)

From Z probability calculator :

P(Z < - 1) = 0.15866

Hence, Probability of obtaining a score less than. 21.8 is 0.15866