Why 500 and 0 is wrong here? And what should they be?

Complete this question by entering your answers in the tabs below. Weighted Perpetual FIFO Perpetual LIFO Average Specific Id Compute the cost assigned to ending inventory using specific identification. For specific identification, units sold consist of 600 units from beginning inventory, 300 from the February 10 purchase, 200 from the March 13 purchase, 50 from the August 21 purchase, and 250 from the September 5 purchase. (Round your average cost per unit to 2 decimal places.) Specific Identification Cost of Goods Available for Sale Cost of Goods Sold Ending Inventory # of # of Cost per unit units Cost of Goods Available for Sale $ 27,000 Cost per unit # of units in ending inventory Cost of Goods Sold 27,000 Cost per unit units Ending Inventory sold 600 $ 45.00 600 $ 45.00 0 $ 45.00 $ 0 400 $ 42.00 12,600 4,200 Beginning inventory Purchases: Feb 10 March 13 Aug 21 Sep 5 16,800 5,400 300 $ 42.00 200 $ 27.00 200 0 $ 27.00 $ 50.00 $ 46.00 100 100 $ 42.00 0 $ 27.00 50 $ 50.00 0 X $ 46.00 50 $ 50.00 5,400 2,500 23,000 5,000 23,000 2,500 500 500 X $ 46.00 0 Total 1,800 $ 77,200 1,650 150 70,500 $ 6,700