HW Problem 5.2 - Robben Co. uses the perpetual inventory system and had the following transactions. A) Calculate the cost of goods available for sale and the number of units available for sale. B) Calculate the units sold in October and the dollar amount recorded for sales. C) Calculate the number of units remaining in ending inventory on 10/31. D) Compute the cost of goods sold and ending inventory values using: specific identification, FIFO, LIFO, and weighted average methods. For the specific identification, assume the remaining inventory includes 15 units from beginning inventory and 25 units from the 9/30 purchase. E) Calculate gross profit earned under each of the costing methods