The following costs result from the production and sale of 4,050 drum sets manufactured by Tight Drums Company for the year ended December 31, 2017. The drum sets sell for $255 each. The company has a 30% income tax rate. Variable production costs Plastic for casing $ 72,900 Wages of assembly workers Drum stands Variable selling costs 336,150 109,350 Sales commissions 64,800 Fixed manufacturing costs 10,500 es on East ce Factory machinery depreciation 81,000 Fixed selling and administrative costs Lease of equipment for sales staff Accounting staff salaries Administrative management salaries 21,000 71,000 151,000 Required 1 Required 2 Compute its contribution margin per unit and its contribution margin ratio. (Round Contribution margin ratio to nearest whole percentage.) TIGHT DRUMS COMPANY Contribution Margin Income Statement (partial) For Year Ended December 31, 2017 Per Unit 255 Sales Variable costs: Plastic for casing Wages of assembly workers Drum stands Sales commissions Total variable costs Contribution margin 111 Contribution Margin Ratio Sales 255 100% Variable costs Contribution margin 111