Question No. 1 (20 minutes) Oak, Inc. had the following income statement for last period: $40,000 24,000 Sales (unit sales price $100) Cost of Sales (manufacturing) Selling and General Administrative Net Income 6,000 $10,000 Assume cost of sales was 75% variable and 25% fixed, and Selling and General Expense was 60% variable and 40% fixed. Required: a. calculate its contribution margin percentage b.calculate the break even sales level in dollars (round to nearest whole dollar) c.calculate the break even level in units (round to nearest whole unit) d.prepare a contribution format income statement