Dave Ryan is the CEO of Ryan's Arcade. At the end of its accounting period, December 31 , Ryan's Arcade has assets of $640,000 and liabilities of $233,950. Using the accounting equation, determine the following amounts: a. Stockholders' equity as of December 31 of the current year. $ b. Stockholders' equity as of December 31 at the end of the next year, assuming that assets increased by $89,540 and liabilities increased by $17,250 during the year. $