Please give me detailed explanation..?

The Rockwell Corporation uses a periodic inventory system and has used the FIFO cost method since inception of the company in 1979. In 2018, the company decided to change to the average cost method. Data for 2018 are as follows: $ 230,100 Beginning inventory, FIFO (5,900 units @ $39.00) Purchases: 5,900 units @ $45.00 5,900 units @ $49.00 Cost of goods available for sale Sales for 2018 (9,800 units @ $79.00) $265,500 289,100 554,600 $784,700 $ 774,200 Additional information: 1. The company's effective income tax rate is 35% for all years. 2. If the company had used the average cost method prior to 2018, ending inventory for 2017 would have been $206,500. 3.7,900 units remained in inventory at the end of 2018. Required: 1. Prepare the journal entry at the beginning of 2018 to record the change in principle. 2. In the 2018-2016 comparative financial statements, what will be the amounts of cost of goods sold and inventory reported for 2018