A crossover trial is a type of experiment used to compare two
drugs. Subjects take one drug for a period of time, then switch to
another. The responses of the subjects are then compared using
matched-pair methods. In an experiment to compare two pain
relievers, seven subjects took one pain reliever for two weeks,
then switched to the other. They rated their pain level from 1 to
10, with larger numbers representing higher levels of pain. Can you
conclude that...