TechGear Inc. uses a periodic inventory system. It entered into the following purchases and sales transactions for November.

Date	Activities	Units Acquired at Cost	Units Sold at Retail
Nov. 1	Beginning inventory	250 units @ $100 per unit
Nov. 4	Purchase	500 units @ $105 per unit
Nov. 12	Sales		400 units @ $150 per unit
Nov. 20	Purchase	350 units @ $110 per unit
Nov. 28	Sales		300 units @ $160 per unit

For specific identification, the November 12 sale consisted of 150 units from beginning inventory and 250 units from the November 4 purchase; the November 28 sale consisted of 200 units from the November 20 purchase and 100 units from the November 4 purchase.

Required:

1. Calculate the cost of goods sold (COGS) using FIFO and LIFO methods.
2. Determine the ending inventory value using the weighted average cost method.
3. Discuss the impact of each inventory costing method on the financial ratios, such as gross margin and current ratio.
4. Analyze the tax implications of using FIFO versus LIFO for TechGear Inc.