Problem 18-1A Contribution margin income statement and contribution margin ratio LO A1 The following costs result from the production and sale of 5,000 drum sets manufactured by Tight Drums Company for the year ended December 31, 2017. The drum sets sell for $350 each. The company has a 25% income tax rate. $185,000 510.000 230,000 175,000 Variable production costs Plastic for casing Wages of assembly workers Drun stands Variable selling costs Sales commissions Fixed manufacturing costs Taxes on factory Factory maintenance Factory machinery depreciation Fixed selling and administrative costs Lease of equipment for sales statt Accounting staff salaries Administrative management salaries 5,000 10,000 70,000 10,000 60.000 140,000 Required: 1. Prepare a contribution margin income statement for the company 2. Compute its contribution margin per unit and its contribution margin ratio