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 (oss) Contribution margin per unit Case #1 Case #2 Case #3 Case #4 10,000 10,000 10,000 $ 180,000 $ 110,000 $ 360,000 120,000 39,000 180,000 $ 20,000 $ 10,000 $ (20,000) $ 20 $ 10 60.000 32,000 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.) Sales Variable expenses Fred expenses Operating income (oss) Average contribution margin (percentage) Case 1 Case #2 $ 450.000 $ 445.000 280.350 145,000 $ 6.000 25% Case 3 Case 14 $ 600,000 420.000 120,000 $ 19.000 $ (4,000) 50%