1.40. Clark, CPA, is engaged in the audit of Tower Wholesaling for the year ended December 31 . Clark obtained an understanding of internal control relating to the purchasing, receiving, trade accounts payable, and cash disbursement cycles and has decided not to proceed with lests of controls. Based upon analytical procedures, Clark believes that the trade accounts payable on the balance sheet as of December 31 may be understated. Clark requested and obtained a client-prepared trade accounts payable schedule listing the total amount owed to each vendor. What additional substantive audit procedures should Clark apply in examining the trade accounts payable