Students in an elementary statistics course argued that their second hour exam was more difficult than their first. The following gives the scores of 15 students on the two exams, each of which had a...

Students in an elementary statistics course argued that their

second hour exam was more difficult than their first. The

following gives the scores of 15 students on the two exams, each

of which had a maximum of 80.

Use the matched-pairs test to test H0: µ1 = µ2 versus

H1 : µ1 > µ2 . Is their evidence that exam scores on the second

exam were lower? Does your answer to this question necessarily

contradict the assertion made?