The following is Allison Corporation's contribution format income statement for December 2014: Sales Less: variable expenses Contribution margin Less: fixed expenses perating income $800,000 300,000 500,000 400,000 $100,000 The company had no beginning or ending inventories. The company produced and sold 10,000 units in December. Required: Assuming no change in either the cost structure or the average selling price, prepare a contribution format income statement for a month Allison Corporation reports no before-tax profit or loss