Comparing the weight of every person in a group of people before they went on a diet with their weight after they completed the diet program. I would want to know whether each person's weight after the program significantly greater than their weight beforehand. 2 sets of groups coming from the same set of people. One set represents the weight before treatment. The other set represents the weight after treatment. In a case like this use a paired-sample t-test. assist with setting up this formula.