A crossover trial is a type of experiment used to compare twodrugs. Subjects take one drug for a period of time, then switch toanother. The responses of the subjects are then compared usingmatched-pair methods. In an experiment to compare two painrelievers, seven subjects took one pain reliever for two weeks,then switched to the other. They rated their pain level from 1 to10, with larger numbers representing higher levels of pain. Can youconclude that the mean pain level is less with drug B? Use