We have collected data on GPA, demographic characteristics and drinking behavior of college students from 119 U.S. colleges in 2001. For this question you will use the same college.dta data set available on Latte but this time use it to explore the impact of drinking behavior on GPA. The main alcohol consumption variable is called drinks. This variable reflects student responses to the question: "In the past 30 days, on those occasions when you drank alcohol, how many drinks did you usually have?" Answers are coded as follows: 0 = did not drink in the past 30 days; 1 = 1 drink, 2=2 drinks, ... up to 9 = 9 or more drinks.

b. Write an equation (again, no need to estimate this in R, simply write down the equation you would like to estimate) that would allow you to test whether alcohol consumption has different 5 effects on GPA for men and women (use the linear version of drinks). How would you test that there are no differences in the effects of alcohol consumption on GPA for men and women? Explain.

c. Estimate the equation in (b) in R and run the test. Is there a difference in how alcohol consumption affects GPA for men and women? Is the difference statistically significant?