Refer to Problems 11 and 12.
a. At the 5% significance level, do the data provide sufficient evidence to conclude that student-to-faculty ratio is useful as a predictor of graduation rate?
b. Determine a 95% confidence interval for the slope, β1, of the population regression line that relates graduation rate to student-to-faculty ratio. Interpret your answer.
Presume that the variables student-to faculty ratio and graduation rate satisfy the assumptions for regression inferences.