Sunland Inc. uses a periodic inventory system. Its records show the following for the month of May, in which 76 units were sold. (a1) Calculate the weighted-average unit cost. (Round answer to 3 decimal places, e.g. 5.125.) Weighted-average unit cost $ eTextbook and Media Attempts: 0 of 15 used (a2) Calculate the ending inventory at May 31 using the FIFO, LIFO and average-cost methods. (Round answers to 0 decimal places, e.g. 125.)