Stroth Corporation uses activity-based costing to compute product margins. Overhead costs have already been allocated to the company's three activity cost pools-Machining, Order Filling, and other. The costs in those activity cost pools appear below: Machining ......... Order Filling....... Other ... ........... $5,400 $2,500 $13,100 Machining costs are assigned to products using machine-hours (MHs) and Order Filling costs are assigned to products using the number of orders. The costs in the Other activity cost pool are not assigned to products. Activity data appear below: Orders (Order Filling) Product CA Product L4....... MHs (Machining) 9,800 200 500 200 500 Finally, sales and direct cost data are combined with Machining and Order Filling costs to determine product margins. Product CA Product L4 Sales (total).... $46,900 $25,300 Direct materials (total)...... $15,100 $11,500 Direct labor (total)... $22,300 $10,900 Required: a. Calculate the activity rate for Machining and order filling under activity-based costing. b. What is the overhead cost assigned to Product C4 under activity-based costing?! c. What is the product margin for Product C4 under activity-based costing