A.C. Tech Manufacturing Appliances manufactures three sizes of kitchen appliances: small, medium, and large. Product information is provided below.

Small Medium Large

Unit selling price $450 $620 $1,240

Unit costs:

Variable manufacturing (240) (280) (530)

Fixed manufacturing (80) (140) (250)

Fixed selling and administrative (110) (125) (130)

Unit profit $20 $75 $330

Demand in units 110 140 110

Machine-hours per unit 40 70 142

The maximum machine-hours available are 6,500 per week.

a. What is the contribution margin for each of the three different size appliances?

b. What is the contribution margin per machine-hour for each of the three different size appliances?

c. If there is excess capacity, which size is the most profitable to produce?

d. If there is NOT excess capacity, which size is the most profitable to produce?