Chapter 10: Q. 96 (page 690)
A study of the impact of caffeine consumption on reaction time was designed to correct for the impact of subjects鈥 prior sleep deprivation by dividing the subjects into pairs on the basis of the average hours of sleep they had had for the previous 5 nights. That is, the two with the highest average sleep were a pair, then the two with the next highest average sleep, and so on. One randomly assigned member of each pair drank cups of caffeinated coffee, and the other drank cups of decaf. Each subject鈥檚 performance on a Page Number: standard reaction-time test was recorded. Which of the following is the correct check of the 鈥淣ormal/Large Sample鈥 condition for this significance test?
I. Confirm graphically that the scores of the caffeine drinkers could have come from a Normal distribution.
II. Confirm graphically that the scores of the decaf drinkers could have come from a Normal distribution.
III. Confirm graphically that the differences in scores within each pair of subjects could have come from a Normal distribution.
a. I only
b. II only
c. III only
d. I and II only
e. I, I, and III
Short Answer
The correct option is c.
c.) III only - Confirm graphically that the differences in scores within each pair of subjects could have come from a Normal distribution.


