(When you first read about this exercise break plan in Chapter 22, you did not have an inference method that would work. Try again now.) A company institutes an exercise break for its workers to see if it will improve job satisfaction, as measured by a questionnaire that assesses workers' satisfaction. Scores for 10 randomly selected workers before and after the implementation of the exercise program are shown in the table below.
a) Identify the procedure you would use to assess the effectiveness of the exercise program, and check to see if the conditions allow the use of that procedure.
b) Test an appropriate hypothesis and state your conclusion.
c) If your conclusion turns out to be incorrect, what kind of error did you commit?
d) Use a matched-pairs sign test to test the appropriate hypothesis. Do your conclusions change from those in part b?

Worker Job Satisfaction Index Number Before fter 28 45 26 50 41 37 24 15 15 27 39 21 20 37 10