The following information is available for a company's cost of sales over the last five months. Month Units sold Cost of sales January 380 $30,200 February 780 $36,000 March 1,500 $48,000 April 2,300 $60,000 Using the high-low method, the estimated variable cost of sales per unit sold is: $26.09. $79.47. $33.66. $15.52. $32.00.