Students were given an exam whose scores are in the column headed exam1. After a special study session, they were retested with the scores in the column headed exam 2. Test the hypothesis that there was no change in their scores. ( = .05)

Exam 1 92 90 85 78 75 80 65 67 65 85 83 90 69 75 56 67 78 92 69 69 90 72 86 80 66 80 70 91 72 80 91 85 69 73 65 96 90 80 81 70 66 75 82 74 92 80 80 91

Exam 2 96 97 88 85 82 88 80 75 67 85 89 93 78 74 67 73 92 97 78 79 94 88 92 84 72 83 76 95 88 84 97 86 75 79 78 96 92 87 86 81 72 80 76 79 97 83 83 93