Westerville Company accumulates the following data concerning a mixed cost, using units produced as the activity level. Units Produced Total Cost March 10,000 $18,000 April 9,000 16,650 May 10,500 18,580 June 8,800 16,200 July 9,500 17,100 (a) Compute the variable- and xed-cost elements using the high-low method. (b) Estimate the total cost if the company produces 9,200 units