A company's ledger accounts and their end-of-period balances before closing entries are posted are shown below. What amount will be posted to retained earnings in the process of closing the Income Summary account? (Assume all accounts have normal balances.) Retained earnings Dividends Revenue Rent expense Salaries expense Insurance expense Depr. Expense-equipment Accum depr.-equipment $ 9,750 13,650 39,000 3,900 9,050 440 680 2,040