A small company, on hearing about the employee athlete program (Exercise 77) at the large company down the street, decides to try it as well. To measure the difference in productivity, they measure the average number of keystrokes per hour of 23 employees before and after the program is instituted. The data follow:

a) Is there evidence to suggest that the program increases productivity?
b) Give a 95% confidence interval for the mean change in productivity (as measured by keystrokes per hour).
c) Given this information and the results of Exercise 77, what recommendations would you make to the company about the effectiveness of the program?

Keystrokes per Hour Difference Before After (After Before) Mean 1497.3 1544.8 155.4 23 47.5 122.8 23 SD 136.7 23