OBJ. 3 PE 7-4A Perpetual inventory using weighted average Beginning inventory, purchases, and sales for 30xT are as follows: May 1 12 23 26 Inventory Sale Purchase Sale 50 units at $80 35 units 60 units at $90 55 units Assuming a perpetual inventory system and using the weighted average method, deter- mine (a) the weighted average unit cost after the May 23 purchase, (b) the cost of the merchandise sold on May 26, and (c) the inventory on May 31