Marin Inc. uses a periodic inventory system. Its records show the following for the month of May, in which 74 units were sold. Total Explanation Inventory Purchase Purchase Total Date Units Unit Cost $310 297 31 27 37 95 $10 May 1 15 24 12 $1,051 Calculate the weighted-average unit cost. (Round answer to 3 decimal places, e.g. 5.125 Weighted-average unit cost Calculate the ending inventory at May 31 using the FIFO, LIFO and average-cost methods. (Round answers to 0 decimal places, e.g. 125.) LIFO AVERAGE-COST FIFO The ending inventory at May 31 s