A test of abstract reasoning is given to a random sample of students before and after they completed a formal logic course. The results are given below.
Before: 74, 83, 75, 88, 84, 63, 93, 84, 91, 77
After: 73, 77, 70, 77, 74, 67, 95, 83, 84, 75
Required:
a. Is there evidence to suggest the logic course improves abstract reasoning?
b. Construct a 95% confidence interval for the mean difference between the before and after scores.