Salomon Marketing, Inc., a merchandising company, reported sales of $1,555,500 and cost of goods sold of $1,025,100 for December. The company's total variable selling expense was $96,900; its total fixed selling expense was $34,300; its total variable administrative expense was $71,400; and its total fixed administrative expense was $100,100. The cost of goods sold in this company is a variable cost. The contribution margin for December is