2.77 Make predictions and compare. Refer to the two previous exercises. Consider a state with a population of 4 million (this value is approximately the median population for the 50 states).
(a) Using the least-squares regression equation for all 50 states, find the predicted number of undergraduate college students.
(b) Do the same using the least-squares regression equation for the 46 states with populations less than 15 million.
(c) Compare the predictions that you made in parts (a) and (b). Write a short summary of your results and conclusions. Pay particular attention to the effect of including the four states with the largest populations in the prediction equation for a median-sized state.