10. Trying to quit smoking? Butt-Enders, a cigarette dependence reduction program, claims to lower the average number of cigarettes smoked for its participants. A sample of 10 participants smoked the following numbers of cigarettes on a randomly chosen day before and after attending Butt-Enders. Assume that the differences are normally distributed.
Participant | 1 | 2 | 3 | 4 | 5 |
Before | 40 | 20 | 60 | 30 | 50 |
After | 20 | 0 | 40 | 30 | 20 |
Participant | 6 | 7 | 8 | 9 | 10 |
Before | 60 | 20 | 40 | 30 | 20 |
After | 60 | 20 | 20 | 0 | 20 |