Mabo Company makes calculators that sell for $20 each. For the coming year, management expects fixed costs to total $220,000 and variable costs to be $9 per unit. Compute: a) Break-even point in units using the mathematical equation. b) Break-even point in dollars using the contribution margin (CM) ratio. c) Margin of safety percentage assuming actual sales are $500,000. d) Sales required in dollars to earn net income of $165,000.