2. Suppose Miguel needed 3 gallons of milk. If he wants to spend the least amount of
money, using any combination of the four sizes above, how much will he spend? Prove that your method guarantees Miguel will spend the least amount of money.

3. Miguel needs ¾ gallons of milk to make 12 milkshakes. How much milk does he need to make 30 milkshakes? Use at least two different methods to support your answer. Is this a proportional relationship?