A professor notes that students in her 3-hour lab seem to get sloppy by the end of the class and make many mistakes in their work. She thinks that the sloppy work is due to fatigue and hypothesizes that providing students with caffeine half way through class will result in students making fewer errors than when they do not have caffeine. To test this hypothesis, she provides the students in the class with a caffeinated drink of their choice and measures the numbers of errors they make. During the same class the next week, she provides students with a decaffeinated version of the same drink and measures the number of errors they make. (5 points)