The following costs result from the production and sale of 4,800 drum sets manufactured by Tight Drums Company for the year ended December 31, 2017. The drum sets sell for $330 each. The company has a 25% income tax rate Variable production costs Plastic for casing wages of assembly workers Drum stands $158,4ee 470,400 201,600 Variable selling costs Sales commissions 148,8ee Fixed manufacturing costs Taxes on factory Factory maintenance Factory machinery depreciation 7,0e0 14,90e 74,900 Fixed selling and administrative costs Lease of equipment for sales staff Accounting staff salaries Administrative management salaries 14,8ee 64,00e 144,8ee Requirec 1. Prepare a contribution margin Income statement for the company 2. Compute its contribution margin per unit and its contribution margin ratio