P6-13B Steward Inc. had a beginning inventory on January 1 of 400 units of product MLN at a cost of $18 per unit. During the year, purchases were as follows: Units Unit Total Cost Cost Feb. 2 1,200 $19 $22,800 May 5 1,00 21 21,000 Aug. 12 1,200 20 24.000 Dec. 8 22 13,200 600 Steward uses a periodic inventory system. At the end of the year, a physical inventory count determined that there were 400 units on hand. Instructions (a) Determine the cost of goods available for sale. (b) Determine the cost of the ending inventory and the cost of goods sold using (1) FIFO and (2) average cost. (Use unrounded numbers in your calculation of the average unit cost but round to the nearest cent for presentation purposes in your answer.)