Shown here is an income statement in the traditional format for a firm with a sales volume of 16,500 units: a $148,500 56,850 $ 91,650 Revenues Cost of goods sold ($9,000 + $2.90/unit) Gross profit Operating expenses: Selling ($2,500 + $0.90/unit) Administration $4,650 + $0.35/unit) Operating income 17,350 10,425 $ 63,875 Required: a. Prepare an income statement in the contribution margin format. b. Calculate the contribution margin per unit and the contribution margin ratio. C. Calculate the firm's operating income (or loss) if the volume changed to 1. 21,500 units. 2. 8,500 units. d. Refer to your answer to part a when total revenues were $148,500. Calculate the firm's operating income (or loss) if unit selling price and variable expense per unit do not change and total revenues 1. Increase by $14,500. 2. Decrease by $9,500