pleases answer part A and B

Fill in the missing amounts in each of the eight case situations below. Each case is independent of the others. 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: 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: (Loss amounts should be indicated by a minus sign.) Case #1 Case #2 Caso #3 Case #4 Sales $ 459,000 $ 195,000 $ 292,000 Variable expenses 134,550 73,000 Fixed expenses 50,000 471,000 Net operating income (108) $ 61.420 $ 93,000 $ (6,000) Contribution margin ratio (percent) 38% % 80%