d. What is the predicted difference in ACT scores between two A students (gpa = 4) who differ in family income by $30,000?

e. What is the predicted difference in ACT scores between two C students (gpa = 2) who differ in family income by $30,000?

f. What might be driving the difference between the answer to d) and e)?

Source SS df MS Number of obs 3, 094 F (5, 3088) 195 . 51 Model 20787 . 6656 5 4157 . 53312 Prob > F 0 . 0000 Residual 65665 . 8228 3, 088 21 . 264839 R-squared 0 . 2404 Adj R-squared = 0 . 2392 Total 86453 . 4884 3 , 093 27 . 951338 Root MSE 4 . 6114 Score Coefficient Std. err. t P> | t | [95% conf. interval] income . 0786912 . 0162392 4 . 85 0 . 000 . 0468505 . 110532 GenderMale 1. 127275 . 1717103 6 .56 0 . 000 7905975 1 . 463953 RaceEthnic . 8421985 . 0705086 11 . 94 0 . 000 70395 . 980447 ResMomHGC . 1526733 . 0289225 5 . 28 0 . 000 . 095964 .2093825 gpaHS 2 . 704341 . 1362558 19.85 0 . 000 2. 437179 2. 971502 cons 10 . 4692 . 5458581 19 . 18 0 . 000 9 . 398918 11 . 53948