A new pill is being studied for its effectiveness for all Americans who are dieting. Suppose researchers want to know if the average weight loss of all people taking the pill for one month is more than the weight loss of dieters who are not taking the pill for a month.
The researchers find 140 random dieting Americans to participate in the experiment.
The researchers split the 140 participants into two groups by asking them who would like to try the new pill, vs which did not want to try it. They end up with 70 people who want to try the pill, and 70 who do not. One group of dieters takes the new pill for a month, and the other group of dieters does not take the pill.
They find, at the end of the statistical analysis, that there is statistically significant evidence that the average weight loss of the group who took the pill was more than the average weight loss of the group of dieters who did not take the pill.
(a) Describe the population of interest.