Answer:
1 1/4 cups of flour
Explanation:
First find the amount for 1 serving.
So you divide the amount of 1 1/2 or 1.50 by 4
1.50/4=.375
Now do .375*7= 2.625 cups of flour
Now you need to subtract the amount you already have which is 4 cups.
2.625-1.50= 1 1/4 cups of flour is what you need left