You would like to know how effective a diet program is at helping people lose weight. 18 over-weight people are randomly selected to participate in the program. They are weighed before and after the program and the results are listed below. Do these results give evidence that the diet program is effective at the 1% significance level?
Participant 1 2 3 4 5 6
Before 185 220 190 158 227 211
After 175 215 195 155 230 207
Participant 7 8 9 10 11 12
Before 260 158 201 300 180 270
After 258 159 201 300 172 272
Participant 13 14 15 16 17 18
Before 293 183 205 151 291 166
After 290 185 200 146 287 166