The following information is available for a company's cost of sales over the last five months. Month January February March April Units sold 540 760 1,400 2,540 Cost of sales $29,400 $35,000 $ 47,000 $59,000 Using the high-low method, the estimated total fixed cost is: $29,600. $42,816. $21,408, $85,632. $23,598