Cost of Goods Sold Formula Steps:

• Identify opening inventory: $240,000 (finished goods, 1 January 2021).
• Add cost of production: $342,000 (goods manufactured during the year).
• Add purchases: $150,000 (acquired during the year).
• Subtract closing inventory to find cost of sales (not provided in the data).

Not enough information to calculate cost of sales, as closing inventory is missing. The given data is ambiguous, with "Purchases 31 December 2021" unclear if it represents closing stock or actual purchases.

Final answer: Not enough information.