Fill in the missing amounts in each of the eight case situations below. Each case is independent of the others. (Hint: One way to find the missing amounts would be to prepare a contribution format income statement for each case, enter the known data, and then compute the missing items.) Required: a. Assume that only one product is being sold in each of the following four case situations: Unit sold Sales Variable expenses Fixed expenses Operating income (loss) Contribution margin per unit Case #1 Case #2 Case #3 Case #4 18,000 12,000 7,200 $ 216,000 $ 120,000 $ 360,000 144,000 84,000 60,000 38,400 120,000 $ 9,600 $ 14,400 $ (12,000) $ 10 $ 13