11.19 Predicting college debt: Inference. Refer to the previous exercise. Let’s proceed using the data set without Baruch College.

  1. (a) Report the least-squares equation using all four variables.

  2. (b) What percent of the variability in average debt is explained by this model?

  3. (c) Report the F statistic, its degrees of freedom, and the P-value. What do you conclude based on this test result?

  4. (d) Using this F test and the individual parameter t tests, write a one-paragraph summary of this model’s fit to the data.