Using proportions, it is found that you need 900 quarts of brown stock to make the servings of mushroom gravy.
A proportion is a fraction of a total amount, and the measures are related using a rule of three.
In this problem, each serving takes 75 cups of brown stock = 75/4 = 18.75 quarts.
48 servings will be made, hence the number of quarts is given by:
nQ = 48 x 18.75 = 900 quarts.
More can be learned about proportions at https://brainly.com/question/24372153
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