11. When calculating contribution margin, all of the items below are needed except a. Sales Price and Sales in units b. Variable product expenses c. Variable period expense d. Gross Profit Assume a merchandising company's estimated sales for January, February, and March are $100,000,$120,000, and $110,000, respectively. Its cost of goods sold is always 40% of its sales. The company always maintains ending merchandise inventory equal to 10% of next month's cost of goods sold. What are the required merchandise purchases for February