Concord Company started operations on January 1, 2015, and has used the FIFO method of inventory valuation since its inception. In 2021, it decides to switch to the average-cost method. You are provided with the following information. Net Income Retained Earnings (Ending Balance) Under FIFO Under Average-Cost Under FIFO 2015 $98,000 $88,100 $102,500 2016 68,100 63,600 161,100 2017 90,900 81,500 234,200 2018 108,100 118,200 336,600 2019 324,300 313,800 595,400 2020 303,200 308,200 742,200 (a) What is the beginning retained earnings balance at January 1, 2017, if Concord prepares comparative financial statements starting in 2017