P6-9A Terando Co. began operations on July 1. It uses a perpetual inventory system. During July, the company had the following purchases and sales. July 1. Units 5 Unit Cost $120 Sales July 6. Sales Units 4 July 11. Units 7 Unit Cost $136 July 14. Sales Units 3 July 21. Units 8 Unit Cost $147 July 27. Sales units 6 a) Determine the ending inventory under a perpetual inventory system using (1) FIFO, (2) moving-average cost, and (3) LIFO. b) Which costing method produces the highest ending inventory valuation?