Yardley, CPA, prepared the flowchart on the following page, which por- trays the raw materials purchasing function of one of Yardley's clients, a medium-size manufacturing company, from the preparation of initial documents through the vouching of invoices for payment. The flowchart represents a portion of the work performed on the audit engagement to evaluate internal control. Required: Identify and explain the control weaknesses evident from the flowchart. Include the internal control weaknesses resulting from activities per- formed or not performed. All documents are prenumbered. (AICPA, adapted) P-963