Riverbed Corp uses a periodic inventory system. Its records show the following for the month of May, in which 75 units were sold. Date Units May 1 15 Explanation Inventory Purchase Purchase Total 34 26 40 100 Unit Cost $8 9 10 Total Cost $272 234 400 $906 24 (a) Your answer is correct. Calculate the weighted average unit cost. (Round answer to 3 decimal places, e.g. 5.125.) $ 9.06 Weighted-average unit cost (b) Calculate the ending inventory at May 31 using the FIFO, LIFO and average-cost methods. (Round answers to decimal places, e.g. 125.) FIFO LIFO AVERAGE-COST The ending inventory at May 31 $ $