Final answer:
Dexter should show a balance of $920,000 in the investment account at December 31, 2012.
Step-by-step explanation:
Assuming the investment in Brown Corporation remained unchanged throughout the year, Dexter should show a balance of $920,000 in the investment account at December 31, 2012. This can be calculated using the following formula:
New investment account balance = Beginning balance + (Proportion of earnings attributable to Dexter - Proportion of dividends received by Dexter)
Proportion of earnings attributable to Dexter = (Earnings of Brown Corporation * Number of shares owned by Dexter) / Total shares outstanding = ($600,000 * 3,000) / 10,000 = $180,000
Proportion of dividends received by Dexter = (Dividends paid by Brown Corporation * Number of shares owned by Dexter) / Total shares outstanding = ($200,000 * 3,000) / 10,000 = $60,000
New investment account balance = $800,000 + ($180,000 - $60,000) = $920,000