A dietitian wishes to see if a person’s cholesterol level will change if the diet is supplemented by a certain mineral. Six subjects were pretested, and then they took the mineral supplement for a 6-week period. The results are shown in the table. (Cholesterol level is measured in milligrams per deciliter.) Can it be concluded that the cholesterol level has been changed at level of 0.10? Assume the variable is approximately normally distributed.
Subject 1 2 3 4 5 6
Before (x1) 210 235 208 190 172 244
After (x2) 190 170 210 188 173 288