Dave Ryan is the owner and operator of Ryan's Arcade. At the end of its accounting period, December 31, Ryan's Arcade has assets of $640,770 and liabilities of $229,010. Using the accounting equation, determine the following amounts:

a. Owner's equity as of December 31 of the current year.

b. Owner's equity as of December 31 at the end of the next year, assuming that assets increased by $85,010 and liabilities increased by $18,720 during the year.