PE 7-4A Perpetual inventory using weighted average OBJ. 3 Beginning inventory, purchases, and sales for H76 are as follows: July 1 Inventory 300 units at $120 12 Sale 210 units 23 Purchase 360 units at $135 26 Sale 330 units Assuming a perpetual inventory system and using the weighted average method, deter- mine (a) the weighted average unit cost after the July 23 purchase, (b) the cost of the mer- chandise sold on July 26, and (c) the inventory on July 31