Exam 2024
a) Define the null and alternative hypothesis for the following. Also, explain what it would mean to
make a Type I error and explain what it would mean to make a Type II error.
The newspaper in a certain city had a circulation of 15,000 per day in 2010. You believe that the
newspaper’s circulation is more than 15,000 today.
H0: u= 15,000
H1: u > 15,000
Type I Error: Reject the null hypothesis that the mean number of newspaper circulations is 15,000
per day when the mean number of newspaper circulations is not greater than 15,000 per day.
Type II Error: Do not reject the null hypothesis that the mean number of newspaper circulations is
15,000 per day when the mean number of newspaper circulations is greater than 15,000 per day.
b) Define the null and alternative hypothesis for the following. Also, explain what it would mean to
make a Type I error and explain what it would mean to make a Type II error.
A certain website had 3500 hits per month a year ago. You believe that the number of hits per month
is less than that today.
, H0: u= 3500
H1: u<3500
Type I Error: Reject the null hypothesis that the website gets 3500 hits per month when that
websites gets at least 3500 hits per month.
Type II Error: Do not reject the null hypothesis when the number of hits per month the websites gets
is less than 3500.
Instructor Comments
Very good.
Answer Key
a) Define the null and alternative hypothesis for the following. Also, explain what it would mean to
make a Type I error and explain what it would mean to make a Type II error.
The newspaper in a certain city had a circulation of 15,000 per day in 2010. You believe that the
newspaper’s circulation is more than 15,000 today.
a) H0: μ=15,000.
H1:μ>15,000.
Type I error: Reject the null hypothesis that the circulation today is 15,000 when the circulation today
is no more than 15,000.