I don't understand completely. So I need to get answer and explanation.

1, Siena Melamine Factory uses process costing. It has two departments: Mixing and Finishing. The Finishing Department receives the mixed components from the Mixing Department and finishes them. 60% of the materials are added at the beginning of the process in the Finishing Department, and the remaining 40% are added when the units are 80% complete. Finishing's beginning Work in Process amounts to 8,000 units which are 40% complete as to conversion costs. Finishing received 40,000 units from Mixing. Finishing's ending Work in Process amounted to 15,000 units that are 90% complete as to conversion costs. The costs of beginning Work in Process are $96,000 in transferred in costs, $19,200 in materials, and $9,600 in conversion costs. Costs added during the period included $500,000 in transferred in costs, $194,400 in material costs, and $129,900 in conversion costs. Siena uses the FIFO method. 2, Payam Textile Company has a work in process inventory of 250 yards that is 80% complete with regard to conversion. 80% of the material is added at the beginning of the process, and the remaining 20% is added at the end of the process. Payam started 9,250 yards into production, and completed 7,200 good yards. Normal spoilage amounts to 5% of the good yards completed. Total spoilage for the accounting period amounted to 850 yards. Inspection occurs when the process is 70% complete. Ending Work in Process for the period was 90% complete for conversion costs. The cost of beginning Work in Process is $3,500 ($2,500 for materials and $1,000 for conversion). Total cost added during the accounting period was $223,340, of which $96,940 was material cost. Payam uses the Weighted Average method