The solution provided previously is confusing and does not answer the question for (a). Please help!

2. Tom's Trains produces wooden toy trains and uses process costing. Each train passes through three processescutting, assembly, and finishing. In the Assembly Department, materials are added when the trains are 60% complete, and conversion costs are added evenly throughout the process. Production information for the Assembly Department for July follows: Ending Work in Process, conversion costs 40% complete Beginning Work in Process, conversion costs 70% complete Units started during July 41,000 Units in Work in Process, July 1 5,200 Units in Work in Process, July 31 7,000 Conversion costs in beginning Work in Process $31,000 Transferred-in costs in beginning Work in Process $16,820 Cost of direct materials in beginning WIP $11,280 Conversion costs added during July $21,500 Direct material cost added during July $24.,000 Transferred-in costs added during July $34,000 a. Calculate the equivalent units for the Assembly Department for July. b. Identify the nature of 'transferred-in' costs and how these costs differ from costs in the beginning Work in Process iventory as it relates to the Assembly Department