On May 1 cullumber company had beginning inventory consisting of 252 units with a unit cost of $5. During May the company purchased inventory as follows. 504 units at $5. 756 units at 6 dollar. The company sold 1260 units during the month for $9 dollar per units.Cullumber uses the average cost method. Assuming that a periodic inventory system is used, the cost of cullumber inventory at May 31 is as follows