Contribution margin Willie Company sells 27,000 units at $21 per unit. Variable costs are $15.12 per unit, and fixed costs are $47,600. Determine (a) the contribution margin ratio, (b) the unit contribution margin, and (c) operating income. a. Contribution margin ratio (Enter as a whole number.) b. Unit contribution margin (Round to the nearest cent.) c. Operating income % 9 per unit $