The data represent the weight of twentyfive people who went
The data represent the weight of twenty-five people who went on a prescribed diet at the beginning of a one- year time period. The Before weights are their weights at the start of the program and After sre their weights one year later.
a) Use the formula below to test the hypothesis that weight before equals weight after against the alternative that weight after is less than before, and indicate your conclusion.
T = d¯ xb-xa/ S.E. d¯
| Person | Before | After |
| 1 | 173 | 164 |
| 2 | 192 | 191 |
| 3 | 185 | 176 |
| 4 | 177 | 176 |
| 5 | 196 | 189 |
| 6 | 178 | 169 |
| 7 | 196 | 196 |
| 8 | 181 | 172 |
| 9 | 158 | 158 |
| 10 | 201 | 193 |
| 11 | 191 | 185 |
| 12 | 193 | 190 |
| 13 | 176 | 175 |
| 14 | 212 | 210 |
| 15 | 177 | 173 |
| 16 | 183 | 180 |
| 17 | 211 | 204 |
| 18 | 198 | 192 |
| 19 | 157 | 152 |
| 20 | 213 | 209 |
| 21 | 161 | 153 |
| 22 | 177 | 168 |
| 23 | 210 | 203 |
| 24 | 192 | 186 |
| 25 | 178 | 170 |
Solution
