(Please help me understand your answer to the questions. I got four of them wrong, and I wasn't told why or which ones.)

An investigator believed that people who smoke tend to smoke more during periods of stress. She compared the number of cigarettes ordinarily smoked in a24-hour period, by a group of 15randomly selected students versus the 24hours prior to final examinations. hypothesis test to determine if the data supports the investigator's prediction that people smoke more during periods of stress using an alpha level of?= .05, one-tailed.

Typical Day (Before Stress) 24 Hrs Prior to Finals (After Stress) X2-X1 X1 X2 D D2 9 8 14 12 21 26 13 14 16 18 8 7 10 8 32 39 U OO W N A N N NJ N -UN 4 - A - M 4 49 35 33 4 17 21 16 16 18 15 12 17 25 64 8 8 0 11 16 25 M1= 17.67 M2 = 16.13 ED=23 ED2=211 $1 = 10.97 S2 = 5.14