10.39 More on public university tuition. Refer to the previous exercise. We’ll now move forward with inference using the model fit you chose in part (f) of the previous exercise.
(a) Give the null and alternative hypotheses for examining if there is a linear relationship between 2008 and 2014 tuition amounts.
(b) Write down the test statistic and P-value for the hypotheses stated in part (a). State your conclusions.
(c) Construct a 95% confidence interval for the slope. What does this interval tell you about the annual percent increase in tuition between 2008 and 2014?
(d) What percent of the variability in 2014 tuition is explained by a linear regression model using the 2008 tuition?
(e) Explain why inference on β0 is not of interest for this problem.