Fill in the missing amounts in each of the four 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.) \begin{tabular}{|c|c|c|c|c|c} UnitsSold & Sales & VariableExpenses & ContributionMarginperUnit & FixedExpenses & NetOperatingIncome \\ \hline 20,000 & $300,000 & $220,000 & ? & $45,000 & ? \\ 12,000 & ? & $120,000 & $15 & ? & $18,000 \\ \hline \end{tabular} Required: 1. Cases A and B assume that only one product is being sold. 2. Cases C and D assume that more than one product is being sold