Underwood, Inc. manufactures two products. It currently has 9,800 hours of direct labor and 2,200 hours of machine time available per month. The table below lists the contribution margin, labor and machine time requirements, and demand for each product Product A Product B Unit contribution margin $19.00 $15.00 Demand 3,000 units 1,500 units 1/2 hour Labor time 1/2 hour Machine time 3 hour 1/2 hour What is the contribution margin per mach ine hour for Product B