The College Board finds that the distribution of students' SAT scores depends on the level of education their parents have. Children of parents who did not finish high school have SAT math scoresXwith mean454and standard deviation109. ScoresYof children of parents with graduate degrees have mean553and standard deviation102. Perhaps we should standardize to a common scale for equity. Find numbersa,b,c, anddsuch thata+bXandc+dYboth have mean 500 and standard deviation 100. (Round your answers to two decimal places.)

a =

b =

c =

d =