Spin Cycle Company uses three activity pools to apply overhead to its products. Each activity has a cost driver used to allocate the overhead costs to the product. The activities and related overhead costs are as follows: product design $47,200; machining $351,000; and material handling $117,970. The cost drivers and estimated use are as follows. Estimated Use of Cost Drivers per Activity Activities Activity Cost Pools Product design Machining Material handling 10 Number of product changes Machine hours Number of set-ups 135,000 94 (a) Calculate the predetermined overhead rate for each activity. (Round overhead rate for machining activity to 2 decimal places, e.g. 15.25.) Activity Overhead Rate Product design per product change $ Machining per machine hr. $ Material handling per set-up $