D. Herschel Supply Co. makes student book bags that sell for $20 each. For the coming year, management expects fixed costs to be $225,000. Variable costs are $14 per unit. Instructions 1. Compute break-even sales in dollars using the mathematical equation. 2. Compute break-even sales using the contribution margin ratio. 3. Compute margin of safety ratio assuming actual sales are $937,500. 4. Compute the sales required to earn net income of $150,000, using the mathematical equation