Final answer:
The Cooper family drinks at a rate of 1/6 gallon of milk per day, calculated by dividing 1/2 gallon by 3 days.
Step-by-step explanation:
The question we are looking at is determining the rate at which the Cooper family drinks milk. To find this rate, we will analyze the consumption pattern. They consume a 1/2 gallon of milk every 3 days.
The rate of milk consumption can be found by setting up a proportion, dividing the quantity of milk consumed (1/2 gallon) by the number of days it is consumed in (3 days). This calculation gives us:
Rate of milk consumption = (1/2 gallon) / 3 days = 1/6 gallon per day.
This means the Cooper family drinks 1/6 of a gallon of milk each day. This unit of measurement is appropriate considering the quantity they use and the period over which it is used.