Mabbie Corponation uses activity-based costing to compute product margins. Overisead costs have onready been allocated to the companys three activity cost pools-Processing. Supervising. and Other. The costs in those activity cost pools appear below: Processing costs are assigned to products using machine hours (MHs) and Supervising costs are assigned to products using the number of batches. The costs in the Other activity cost poot are not assigned to products. Activity data appear below. Finally sales and direct cost data are combined with Processing and Supervising conts to determine product margins. The activity rate for the Supervising activity cost pool under activity-based costing is closest to: Muttiple Choice $750 per batch $2220 per batch $3195 per botch $2595 per batch