A school psychologist wishes to determine whether a newanti-smoking film actually reduces the daily consumption ofcigarettes by teenage smokers. The mean daily cigarette consumptionis calculated for each of eight teenage smokers during the monthbefore and the month after the film presentation, with thefollowing results: MEAN DAILY CIGARETTE CONSUMPTION
SMOKER NUMBER BEFORE FILM (X1) AFTER FILM (X2)
1 28 26
2 29 27
3 31 32
4 44 44
5 35 35
6 20 16
7 50 47
8 25 23
A) Is there a significant difference in the number of cigarettessmoked before the film as compared to the number of cigarettessmoked after the film?
B) What does this NOT necessarily mean?
C) What might be done to improve the design of thisexperiment?
