The following costs result from the production and sale of 4,250 drum sets manufactured by Tight Drums Company for the year ended December 31, 2017. The drum sets sell for $275 each. The company has a 30% income tax rate. Variable production costs Plastic for casing $ 93,500 Wages of assembly workers 369,750 Drum stands 131,750 Variable selling costs Sales commissions 85,000 Fixed manufacturing costs Taxes on factory 12,500 Factory maintenance 25,000 Factory machinery depreciation 85,000 Fixed selling and administrative costs Lease of equipment for sales staff 25,000 Accounting staff salaries 75,000 Administrative management salaries 155,000 Required: 1. Prepare a contribution margin income statement for the company. 2. Compute its contribution margin per unit and its contribution margin ratio.