The following costs result from the production and sale of 4,450 drum sets manufactured by Tight Drums Company for the year ended December 31, 2019. The drum sets sell for $295 each. The company has a 30% income tax rate. Variable production costs Plastic for casing $ 115,700 Wages of assembly workers 404,950 Drum stands 155,750 Variable selling costs Sales commissions 106,800 Fixed manufacturing costs Taxes on factory 14,500 Factory maintenance 29,000 Factory machinery depreciation 89,000 Fixed selling and administrative costs Lease of equipment for sales staff 29,000 Accounting staff salaries 79,000 Administrative management salaries 159,000 Required: 1. Prepare a contribution margin income statement for the year. 2. Compute its contribution margin per unit and its contribution margin ratio.