Joe is taking a bowling course for his physical education elective in college. He wonders whether the course significantly improves students’ bowling averages. He records his and his fellow students’ bowling averages at the beginning of the course and again at the end of the course. Here are the scores:

a. Calculate t, and compare it with a one-tailed critical t at the .05 α level. Did the course result in significantly higher bowling averages?

b. The design of this study is not ideal because it is possible that students’ bowling averages would have gone up over the semester even without instruction. How could the design of this study be changed to eliminate this problem?

Participant Amy Brad Carlos Desi Elena Frank Glenda Hal Ingrid Joe Kessa LaShawna Missy Nate Bowling Average Before the Course 72 162 145 183 123 167 76 112 124 137 146 92 166 93 Bowling Average After the Course 91 155 152 190 134 175 99 104 134 156 134 101 168 90