Shown here is an income statement in the traditional format for a firm with a sales volume of 7,900 units. Cost formulas also are shown: Cost of goods sold ($5,700+ $2.20/unit) Gross proft Operating expenses: $34,200 23,080 $11,120 Selling ($1,180+$0.09/unit) Administration ($3,550+ $O.20/unit) 1,891 5,130 $ 4,099 Operating income Required: a. Prepare an income statement in the contribution margin format. Contribution Margin Income Statement Revenue Variable expenses: Cost of goods sold Selling expenses Administrative expenses Total variable expenses Contribution margin Cost of goods sold Selling expenses Administrative expenses Total foxed expenses Operating income