Answer:
4/5 of a quart
Step-by-step explanation:
Set this up as a proportion. First of all we know that 4 quarts of organic grapes cost $20, so 4x = 20. Divide and you get that x = 5 meaning 1 quart equals 5 dollars. Now if we scale this down a bit and divide by 5, we end up with 4/5 of a quart = 1$.
Hope this helped (: