MBAs R Us advertises that its program increases a person’s score on the GMAT by an average of forty points. As a way of checking the validity of that claim, a consumer watchdog group hired fifteen students to take both the review course and the GMAT. Prior to starting the course, the fifteen students were given a diagnostic test that predicted how well they would do on the GMAT in the absence of any special training. The following table gives each student’s actual GMAT score minus his or her predicted score. Set up and carry out an appropriate hypothesis test. Use the 0.05 level of significance.

25 360 89 56 44 600- 071271 7 301 pt 40 3 3 3 3 2 4 4 4 4 5734805683 6