1. Dr. Smith conducted an experiment to study the effects of massed versus distributed practice on memory. Twelve participants were randomly assigned to study a short chapter of a history text during either a single 3-hour session or 3 one-hour sessions separated by 24 hours. Twenty-four hours after the study session(s) ended, the participants took an examination on the information in the chapter and the number of correct answers was recorded. Data from that experiment are shown below. Massed Practice Distributed Practice 55 74 67 67 55 87 47 77 59 68 70 75 X1 = 58.83 X2 = 74.67 S1 = 8.50 S2 = 7.23 2. A researcher wants to see if antihistamines will increase the amount of time in seconds it takes participants to react to a surprise stimulus. He first collects the participants' reaction times while not on antihistamines, and then gives them the dose of antihistamine. One hour later, he collects the participants' reaction times again. Participant ID Reaction Time Reaction Time Before Antihistamine After Antihistamine 1 1.37 1.45 2 2.45 2.90 3 1.95 2.01 4 3.01 3.25 5 .95 1.07 6 1.50 1.71 7 2.05 2.07 8 2.31 2.30 9 3.07 3.15 10 1.99 2.11 Mean 2.065 2.202 Standard .68 .72 Deviation