A cake recipe calls for 1.5 cups of milk and 3 cups of flour. Stephen made a mistake and used 7 cups of flour. How many cups of milk should he use to keep the proportions correct?

he should use 3.5 cups of milk.

bc three goes into seven 2 1/3 times.

and 1/3 of 1.5 is 0.5

since 3 goes into 7, 2 times, he uses 3 cups of milk, and sinze 1/3 of 1.5 is 0.5, add them together and you get 3.5

i hope that made sense