while trying to find the dollar value lifo method please explain why you dont use the index 1.20 to find any of the ending inventories? i dont understand how dollar value lifo method works.

Inventory at End-of-Year Prices Index $ 200,000 1.00 Year 2017 Inventory at Base-Year Base Prices Layers 200,000 $200,000 $ Value $ Value LIFO LIFO LIFO TOTAL Reserve $ 200,000 $200,000 $ Index 1.00 2018 299,000 1.15 260,000 200,000 60,000 1.00 1.15 200,000 69,000 269,000 30,000 2019 300,000 1.20 250,000 200,000 50,000 1.00 1.15 200,000 57,500 257,500 42,500 2020 351,000 1.30 270,000 200,000 50,000 20,000 1.00 1.15 1.30 200,000 57,500 26,000 283,500 67,500 Balance Sheet Inventory Allowance to Reduce Inventory to LIFO Net book value Dec. 31 Dec. 31 Dec. 31 Dec. 31 2017 2018 2019 2020 $ 200,000 $ 299,000 $ 300,000 $ 351,000 (30,000) (42,500) (67,500) $ 200,000 $ 269,000 $ 257,500 $ 283,500 Journal entry Cost of Goods Sold Allowance to Reduce Inventory to LIFO 30,000 (30,000) 12,500 (12,500) 25,000 (25,000)