Beginning inventory, purchases, and sales data for watches are as follows:

a. Assuming that a perpetual inventory system is used, costing by the FIFO method, determine the cost of goods sold for each sale and the inventory balance after each sale, presenting the data in the form illustrated in Exhibit 3, on page 310.
b. Assuming that the perpetual inventory system is used, costing by the weighted average method, determine the cost of goods sold for each sale and the inventory balance after each sale, presenting the data in the form illustrated in Exhibit 4, on page 311.

Inventory Purchases Sales May 1 850 units at $112 May 8 320 units at $120 98 units at $132 May 10 15 30 600 units 405 units 172 units 19