Casey Jones is an auditor on the High End Limited audit engagement for the year ended 30 June 2012. Jimmy has performed a number of tests in relation to accounts payable. A number of suppliers were selected from the list of trade creditors at year end and balances traced to supplier invoices and goods received notes to ensure goods were received prior to the year end. For two creditors out of 15 tested the balance was only marginally overstated. Casey accepted the result as no material errors located. Required: Identify whether this is a test of control or substantive test of detail and discuss why the conclusion reached is appropriate or inappropriate.