Could you tell why my ans. is incorrect and how to find the numbers for Avg. cost method periodic?

Problem 8-7 Various inventory costing methods [LO8-1,8-4) Carlson Auto Dealers Inc. selis handmade automobile as its only product. Each automobile is identical; however they can be distinguished by their unique ID number. At the beginning of 2018, Carlson had three cars in inventory, as follows: $69,000 72.800 During 2015, each of the three autos sold for 599,000. Additional purchases listed in chronological order and sales for the year were as follows: Car ID 211 212 Cost 569.00 69.800 214 72.000 75.000 Selling Price $ 99,000 102,080 not sold 105, 109,5 not sold 114,000 115,500 not sold 23.5 78.99 75,383 219 Required: 1. Calculate 2018 ending inventory and cost of goods sold assuming the company uses the specific identification inventory method 2. Calculate ending inventory and cost of goods sold assuming HFO and a periodic inventory system. 3. Calculate ending inventory and cost of goods sold assuming LIFO and a periodic inventory system 4. Calculate ending inventory and cost of goods sold assuming the average cost method and a periodic inventory system Answer is complete but not entirely correct. 3 Ending intory Cost of goods sold 225.000 648,300 23000 639,000 210 000 0 53,300 1655 497,475