E6-10 (Algo) Calculating Contribution Margin, Contribution Margin Ratio, Margin of Safety [LO 6-2, 6-3] Last month, Laredo Company sold 510 units for $55 each. During the month, fixed costs were $5.478 and variable costs were $22 per unit. Required: 1. Determine the unit contribution margin and contribution margin ratio, 2. Calculate the break-even point in units and sales dollars. 3. Compute Laredo's margin of safety in units and as a percentage of sales.