a. Should hsizeibe included in the model? {6 points} b. Holding hsize fixed what is the difference in SAT score between non black males and non black females. Is this statistically significant? {6 points} c. What is the estimate difference between black males and nonblack males. Is this difference statisticallyI significant? {:5 points] d. What is the estimated difference between black females and nenblack females? Can you use the t statistic for [35 to test if this is statistically significant? {If points}