Restate the following income statement for a retailer in contribution format. Sales revenue ($100 per unit) $ 82,000 Less cost of goods sold ($62 per unit) 50,840 Gross margin 31,160 Less operating costs: Commissions expense ($7 per unit) $ 5,740 Salaries expense 7,800 Advertising expense 5,800 Shipping expense ($3 per unit) 2,460 21,800 Operating income $ 9,360 Per Unit $ $