In order to determine whether or not a driver's education course improves the scores on a driving exam, a sample of 6 students were given the exam before and after taking the course. The results are shown below.
Let d = Score After - Score Before.

Score Score
Student Before the Course After the Course
1 83 87
2 89 88
3 93 91
4 77 77 5 86 93
6 79 83

a. Compute the test statistic.
b. At 95% confidence using the p-value approach, test to see if taking the course actually increased scores on the driving exam.