The following information is available for a company's cost of sales over the last five months. Month January February March Units sold 480 880 2,000 2,800 Cost of sales $ 34,200 $41,000 $53,000 $ 65,000 April Using the high-low method, the estimated variable cost of sales per unit sold is: Multiple Choice O $23.21 $71.25 O $30.24. o $13.28 $26.50