Terando Co. began operations on July 1. It uses a perpetual inventory system. During July, the company had the following purchases and sales. Date Purchases Units Unit Cost 20 $126 Sales Units $141 July July July July July July 1 6 11 14 21 27 $152 (a1) Calculate the average cost per unit at June 1, 6, 11, 14, 21 & 27. (2) 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