United Merchants Company sells 15,000 units at $14 per unit. Variable costs are $10.92 per unit, and fixed costs are $21,300. Determine (a) the contribution margin ratio, (b) the unit contribution margin, and (c) operating income. a. Contribution margin ratio (Enter as a whole number.) fill in the blank 1 21 % b. Unit contribution margin (Round to the nearest cent.) $fill in the blank 2 per unit c. Operating income $fill in the blank 3