Shown here is an income statement in the traditional format for a firm with a sales volume of 18,000 units $234,000 63,700 $170,300 Revenues Cost of goods sold ($11,500+$2.90/unit) Gross profit Operating expenses 20,300 12,100 $137,900 Selling ($2,300+$1.00/unit) Administration ($4,900+ $0.40/unit) Operating income Required: a. Prepare an income statement in the contribution margin format Contribution Margin Income Statement Variable expenses Total variable expenses Fixed expenses Total fixed expenses b. Calculate the contribution margin per unit and the contribution margin ratio. (Do not round intermediate calculations. Round your answers to 2 decimal places.) Contribution margin per unit Contribution margin ratio . Caculate the frm's operating income (or loss) f the volume changed from 18.000 units to 23,000 unts.(Do not round intermediate calculations.) c-2. Calculate the firm's operating income (or loss) if the volume changed from 18,000 units to 10,000 units. (Do not round intermediate calculations.) Refer to your answer to part a when total revenues were $234,000 d-1. Calculate the firm's operating income (or loss) If unit selling price and variable expense per unit do not change and total revenues increase by $15,000. (Do not round intermediate calculations.) d-2. Calculate the firm's operating income (or loss) if unit selling price and variable expense per unit do not change and total revenues decrease by $7,500. (Do not round intermediate calculations.)