Contribution Margin United Merchants Company sells 25,000 units at $10 per unit. Variable costs are $6.10 per unit, and fixed costs are $45,800. 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.) per unit c. Operating income 96