Using the regression results in column (3): a. Are there any important regional differences? Use an appropriate hypothesis test to explain your answer. b. Juan is a 32-year-old male high school...

Using the regression results in column (3):

a. Are there any important regional differences? Use an appropriate hypothesis test to explain your answer.

b. Juan is a 32-year-old male high school graduate from the North. Mel is a 32-year-old male college graduate from the West. Ari is a 32-year-old male college graduate from the East.

i. Construct a 95% confidence interval for the difference in expected earnings between Juan and Mel.

ii. Explain how you would construct a 95% confidence interval for the difference in expected earnings between Juan and Ari. (Hint: What would happen if you included West and excluded East from the regression?)