Question 9 3 pts To gather evidence that uncollected items in customers' accounts represent valid trade receivables, the auditor should select a sample of items from the population represented by the: Customer order file Bill of lading file. Sales invoice file. Accounts receivable master file. Question 10 3 pts Shipping documents should be traced and compared with sales records or invoices to: Ascertain whether all sales are supported by shipping documents. Assure that shipments are billed to customers. Determine whether payments are properly applied to customer accounts. O Determine whether unit prices billed are in accordance with sales contracts