Suppose I recorded the attendance of my students in a recent statistics class because I wanted to investigate the linear relationship between the number of classes they missed and their final grades. The following table shows these data for a random sample of nine students. Use formulas on pages 659, 661, 664, 665, and 667.

missed classes final grade

4 74

6 79

1 93

4 70

0 96

2 84

0 90

5 86

2 95

a) Calculate the coefficient of determination

b) Using alpha - .05, test the significance of the population coefficient of determination.

c) Construct a 95% confidence interval for the average grade of students who missed two classes.

d) Construct a 95% prediction interval for the grade of a student who missed two classes.