Required: a. Assume that only one product is being sold in each of the four following case situations: b. Assume that more than one product is being sold in each of the four following case situations: (For all requirements, Loss amounts should be indicated by a minus sign.) Complete this question by entering your answers in the tabs below. Required A Required B Assume that more than one product is being sold in each of the four following case situations: Case #1 Case #2 Case #3 Case #4 Sales $ 448,000 $ $ 210,000 136,500 70,000 306,000 85,680 L Variable expenses Fixed expenses Net operating income (loss) Contribution margin ratio (percent) $ $ 474,000 57,000 75 % $ 60,240 38% 1,320 %