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 Unit sold 15,000 5,000 340,000 100,000 $ 15,000 180,000 $ 120,000 55,000 Sales Variable expenses Fixed expenses Operating income (loss) Contribution margin per unit 60,000 38,000 140,000 $ 4,000 $ 85,000 $ (75,000) $ 10 $ 15 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 #3 $ 450,000 Sales Variable expenses Fixed expenses Operating income (loss) Average contribution margin (percentage) Case #2 $ 420,000 264,600 130,000 Case #4 $ 400,000 300,000 120,000 $ 6,800 $ $ (4,800) 18,000 60% 25%