Marwick's Pianos, Inc., purchases pianos from a large manufacturer and sells them at the retail level. The pianos cost, on the average, $2,450 each from the manufacturer. Marwick's Pianos, Inc., sells the pianos to its customers at an average price of $3,125 each. The selling and administrative costs that the company incurs in a typical month are presented below: Costs Selling Cost Formula Advertising Sales salaries and commissions Delivery of pianos to customers Utilities Depreciation of sales facilities 700 per month $950 per month, plus 8% of sales $30 per piano sold S350 per month 0 per month Administrative: Executive salaries Insurance Clerical Depreciation of office equipment $2,500 per month $400 $1,000 per month, plus $20 per piano sold $300 per month per month During August, Marwick's Pianos, Inc., sold and delivered 40 pianos