Suppose we wanted to examine differences in medical expenditure by broad age group and gender. We estimate the following regression on a sample of individuals of ages 20-65:

medical expenditure = 0 + 1Older + 2F emale + 3Older F emale + u

where Older is a binary variable that equals 1 if a person is older than 50 and F emale is a binary indicator that equals 1 if the individual is female. Assume MLR.1-MLR.4 hold. Using the coefficients, write down the expres