E21-34 Computing contribution margin in total, per unit, and as a ratio Complete the table below for contribution margin per unit, total contribution margin, and contribution margin ratio: 1,720 units $ 1,800 720 14,920 units $ 4,500 3,600 4,620 units $ 5,550 1,665 Number of units Sales price per unit Variable costs per unit Calculate: Contribution margin per unit Total contribution margin Contribution margin ratio