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 270 units. Beginning Inventory Purchase Purchase Date January 1 January 15 January 24 Units 140 300 240 Unit Cost $ 75 85 105 Total Cost $ 10,500 25,500 25, 200 Required: 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