The following costs result from the production and sale of 4,350 drum sets manufactured by Tight Drums Company for the year ended December 31, 2017. The drum sets sell for $285 each. The company has a 40% income tax rate Variable production costs Plastic for casing Wages of assembly workers Drum stands 104,400 387,150 143,550 Variable selling costs Sales commissions 95,700 Fixed manufacturing costs Taxes on factory Factory maintenance Factory machinery depreciation 13,500 27,000 87,000 Fixed selling and administrative costs Lease of equipment for sales stafif Accounting staff salaries Administrative management salaries 27,000 77,000 157,000 Required: 1. Prepare a contribution margin income statement for the company 2. Compute its contribution margin per unit and its contribution margin ratico