The Skate Board Company uses a process cost system for making skateboard wheels. Materials are added at the beginning of the process and conversion costs are uniformly incurred. At the beginning of September the work-in-process is 40 percent completer and at the end of the month it is 60 percent complete. Spoilage is detected at the end of the process. Other data for the month include: Beginning work-in-process inventory 1,600 units Units started 20,000 units Units placed in finished goods 12,000 units Ending work-in-process inventory 1,200 units Normal spoilage % on all units finished 20 percent Conversion costs $40,320 Cost of direct materials $40,000 Beginning work-in-process costs: Materials $4,000 Conversion $4,032

a. calculate number of equivalent units?

b. calculate each cost of equalivent units?

c. calculate cost of total units transferred out?

d. calculate cost of ending inventory?