Below are the account balances for Cowboy Law Firm at the end of December. Accounts Balances Cash $ 3,600 Salaries expense 1,300 Accounts payable 1,600 Retained earnings 4,700 Utilities expense 1,100 Supplies 12,000 Service revenue 7,500 Common stock 4,200 Required: Use only the appropriate accounts to prepare an income statement.