Pember Inc. is a retailer operating in Edmonton, Alberta. Pember uses the perpetual inventory method. All sales returns from customers result in the goods being returned to inventory. (Assume that the inventory is not damaged. ) Assume that there are no credit transactions; all amounts are settled in cash. You are provided with the following information for Pember Inc. for the month of January 2014. Calculate average cost for each unit. For each of the following cost flow assumptions, calculate cost of goods sold, ending inventory, and gross profit