PROBLEM 1-21 Traditional and Contribution Format Income Statements L01-6 Marwick's Pianos, Inc., purchases pianos from a large manufacturer for an average cost of $2,450 per unit and then sells them to retail customers for an average price of $3,125 each. The company's selling and administrative costs for a typical month are presented below: Costs Cost Formula Selling: $950 per month, plus 8% of sales $30 per piano sold $350 per month Sales salaries and commissions . . . . . Utilities Depreciation of sales facilities. $800 per month Administrative: $2,500 per month Executive salaries Insurance Clerical Depreciation of office equipment $1,000 per month, plus $20 per piano sold $300 per month