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: Case #1 Case #2 Case #3 Case #4 7,200 Unit sold 18,000 12,000 $ 216,000 $ 120,000 $ 360,000 84,000 Sales Variable expenses Fixed expenses Operating income (loss) Contribution margin per unit 144,000 60,000 38,400 9,600 120,000 (12,000) $ $ 14,400 $ $ 10 $ 13 b. Assume that more than one product is being sold in each of the following four case situations: (Enter "Contribution margin ratio" in percent. Round your final answers to the nearest whole dollar amount.) Case #1 Case #2 Case #3 Case #4 $ 520,000 $ $ 620,000 420,000 273,000 434,000 Sales Variable expenses Fixed expenses Operating income (loss) Average contribution margin (percentage) 105,000 $ 8,000 $ 136,000 26,000 $ 60% (4,800) 20%