Prepare a contribution margin format income statement: answer what-if questions Shown here is an income statement in the traditional format for a firm with a sales volume of 18.000 units: 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 clianged from 18.000 units to I. 20.000 units. 2. 10.000 units. d. Refer to your answer to (a) when total reventles were $10$.000. Calculate the firmis operating income (or loss) if unit selling price and variable expense per unit do nor change and total reventues I. Increase by $15,000 2. Decrease by $10.000