[The following information applies to the questions displayed below.] Martinez Companys relevant range of production is 7,500 units to 12,500 units. When it produces and sells 10,000 units, its unit costs are as follows: Amount Per Unit Direct materials $ 6.00 Direct labor $ 3.50 Variable manufacturing overhead $ 1.50 Fixed manufacturing overhead $ 4.00 Fixed selling expense $ 3.00 Fixed administrative expense $ 2.00 Sales commissions $ 1.00 Variable administrative expense $ 0.50 10. Required information Required: 1. If the selling price is $22 per unit, what is the contribution margin per unit sold? (Round your answer to 2 decimal places.)