Addison, Inc. uses a perpetual Inventory system. Below is information about one inventory item for the month of September Sep. 1 Inventory 20 units at $20 4 Sold 10 units 10 Purchased 30 units at $25 17 Sold 20 units 30 Purchased 10 units at $30 If Addison uses the weighted average cost method, what is the inventory balance at the end of September? a $1,150.00 b. $1,375.00 c. $1,500.00 d. $1,187.50