Question 1161943
Ho: the mean time=18.3 hours/week
Ha: the mean time is not equal to 18.3 hours/wee
alpha=0.02 P{reject Ho|Ho true}
test statistic is a z 
critical value: reject Ho if |z|>2.303
calculation z=(x bar-mean)/sigma/sqrt(48); sigma=sqrt (V)=5.7
z=2.6*sqrt(48)/.5.7
=3.16
reject Ho and conclude that the mean time spent on the Internet is differs from 18.3 hours per week.

p=0.0016