4. Self-Improvement: Memory Professor Adams wrote a book called Improving Your Memory. The professor claims that if you follow the program outlined in the book, your memory will definitely improve. Fifteen people took the professor’s course, in which the book and its program were used. On the first day of class, everyone took a memory exam; and on the last day, everyone took a similar exam. The paired scores for each person follow.

Last exam 225 120 115 275 85 76 114 200 99 135 170 110 216 280 78 First exam 175 110 115 200 60 85 160 190 70 110 140 10 190 200 92 Use a 0.05 level of significance to test the null hypothesis that the scores are the same whether or not people have taken the course against the alternate hypothesis that the scores of people who have taken the course are higher.