Oahu Kiki tracks the number of units purchased and sold throughout each accounting period but applies its inventory costing method at the end of each month, as if it uses a periodic inventory system. Assume Oahu Kiki's records show the following for the month of January. Sales totaled 330 units. Beginning Inventory Purchase Purchase Required: Date January 1 January 15 January 24 Units 180 420 320 Unit Cost $ 75 Total Cost $ 13,500 85 105 35,700 33,600 4 1. Calculate the number and cost of goods available for sale. 2. Calculate the number of units in ending inventory. 3. Calculate the cost of ending inventory and cost of goods sold using the (a) FIFO, (b) LIFO, and (c) weighted average cost methods.