Martinez Company's relevant range of production is 7,500 units to 12,500 units. When it produces and sells 10,000 units, its average costs per unit are as follows: Direct materials Direct labor Variable manufacturing overhead Fixed manufacturing overhead Fixed selling expense Fixed administrative expense Sales commissions Variable administrative expense Average Cost per Unit $ 6.40 $ 3.90 $ 1.40 $ 4.00 $ 3.40 $ 2.10 $ 1.10 $ 0.55 13. If the selling price is $22.40 per unit, what is the contribution margin per unit? (Do not round intermediate calculations. Round your answer to 2 decimal places.) Contribution margin per unit