Simpson Company adds material at the start of production. The following production information is available for September: Beginning Work in Process Inventory (45% to conversion) 30,000 units Started this period 137,500 units Ending Work in Process Inventory (80% to conversion) 9,200 units Beginning Work in Process Inventory Costs: Material $35,500 Conversion 75,905 Current Period Costs: Material $ 64,600 Conversion 130,053 Refer to Simpson Company. What are the equivalent units for material using the weighted average method?

Can you explain how I should start this question?