Why are these incorrect? What am I missing?

Compute the cost assigned to ending inventory using specific identification. For specific identification, units sold consist of 680 units from beginning inventory, 220 from the February 10 purchase, 100 from the March 13 purchase, 80 from the August 21 purchase, and 260 from the September 5 purchase. (Round your average cost per unit to 2 decimal places.) Specific Identification Goods Purchased Cost of Goods Sold Inventory Balance # of Cost Cos per # of units Cost Date per Cost of Goods # of units per nventory units unit sold unit Sold unit Balance January 1 680 @ $ 40.00 $ 27,200.00 February 10 320 @ 35.00 680 @ 40.00= $ 27,200.00 320 @ 35.00 11,200.00 $ 38,400.00 March 13 100 @ 680 @ |40.00 $ 27,200.00 320 @ $ 35.00 $ 11,200.00 100 @ 23.00 $ 2,300.00 $ 40,700.00 March 15 680 @ 40.00 27,20 280 @ 35.00 $ 9,800.00 40 @ 35.00 1.400 100 @ $ 23.00 2,300.00 $28,600.00 $ 12, 100.00 Aug 21 130 @ 45.00 280 @ 35.00 $ 9,800.00 100 @ $ 23.00 2,300.00 130 @ $ 145.00 5,850.00 $ 17,950.00 Sep 5 490 @ 41.00 280 @ 35.00 $ 9,800.00 100 @ $ 23.00 2,300.00 130 @ $ |45.00 5,850.00 490 @ $ 41.00 20,090.00 $ 38,040.00 Sep 10 OX 100 @ 35.00 = $ 3,500.00 100 @ 23.00 2,300.00 50 @ $ 45.00 2,250.00 80 @ $ 45.00 3,600.00 ox @ $ 41.00 O X $ 5,900.00 $ 5,750.00 Totals $ 34,500.00 $ 5,750.00