Contribution Margin by Segment The following data are for Elm Leaf Apparel: East West Sales volume (units): Product XX 6,800 7,500 Product YY 6,000 12,300 Sales price: Product XX $20 $22 Product YY $24 $26 Variable cost per unit: Product XX $12 $12 Product YY $14 $14 a. Determine the contribution margin for Product YY. $ b. Determine the contribution margin for the West Region. $