Explanation:
we can assume that the relationship between the amount and weight of the cookie dough and the amount of included sugar is linear.
in other words the ratio of total weight and amount of sugar is constant.
so,
1 pound of cookies correlates to 3 1/2 ounces sugar.
1/4 pound of cookies correlates to (3 1/2)/4 ounces of sugar.
(3 1/2)/4 = (7/2)/4 = 7/8
1/4 pound of cookies needs 7/8 ounces of sugar.