Understand the concept of Cost of Goods Sold (COGS) under the periodic inventory system. COGS represents the cost of inventory sold during a specific period and is calculated using the formula that accounts for beginning inventory, purchases, and ending inventory.
Recall the formula for COGS under the periodic inventory system: \( \text{COGS} = \text{Beginning Inventory} + \text{Purchases} - \text{Ending Inventory} \). This formula ensures that the cost of goods sold is derived by adding the cost of inventory available for sale and subtracting the inventory that remains unsold at the end of the period.
Analyze the options provided in the problem. Compare each formula to the standard formula for COGS under the periodic inventory system to identify the correct representation.
Option 1: \( \text{COGS} = \text{Purchases} - \text{Beginning Inventory} + \text{Ending Inventory} \). This formula is incorrect because it does not properly account for the relationship between beginning inventory, purchases, and ending inventory.
Option 3: \( \text{COGS} = \text{Beginning Inventory} + \text{Purchases} - \text{Ending Inventory} \). This formula correctly represents the calculation of COGS under the periodic inventory system, as it aligns with the standard formula.