Q 19.13: Yong produces silk and polyester fabrics. Management has compiled the following unit selling price and unit cost information for the fabrics: Sales price/yard Direct materials/yard Direct labor/yard Variable overhead/yard Fixed overhead/yard Variable selling and admin. costs/yard Fixed selling and admin. costs/yard Silk $18.00 4.10 2.70 3.51 2.28 0.90 1.16 Polyester $10.20 0.80 2.90 3.77 1.62 0.60 0.82 Yong uses the same weaving machine to make both types of fabric. It takes 0.5 hours to make 1 yard of polyester fabric and 0.75 hours to make 1 yard of silk fabric. The machine can be operated a total of 5,000 hours per year. What is the contribution margin per machine hour for silk