As part of the engagement team for the audit of JA Tire Manufacturing for the year ended December 31, 2019, you are responsible for auditing the sales and col-lection cycle. Visit the textbook website to download the data file JATireSales.xls pro-vided to your audit firm by the company. The manager has instructed you to read the JA Tire Manufacturing system description provided on the first tab of the Excel file before attempting this assignment to familiarize yourself with the sales process and the relevant worksheets and terminology. This file contains sales transaction information for the year ended December 31, 2019. You will use this data file to perform the following audit procedures. a. Open the data file and review the contents for each of the worksheets (Sales Order, Bills of Lading, Invoice, Cash Receipts, Customer Master, and Product Master). You will work with the Invoice, Sales Order, Bill of Lading, and Customer Master work-sheets for this problem. What columns are included in both the Invoice and Sales Order worksheets? What columns are different between these two worksheets? b. One of the audit objectives you are testing is the occurrence audit objective for sales. Use functions in Excel to determine whether any of the following are present, and if present, identify which observations: i. Duplicate invoice numbers in the Invoice worksheet ii. Duplicate customer purchase order numbers in the Sales Order worksheet iii. Bills of lading and invoices with repeated sales order numbers in the Bill of Lading and Invoice worksheet, respectively iv. Sales orders in the Sales Order worksheet without a customer purchase order, but that were shipped (as evidenced by a bill of lading in the Bill of Lading worksheet) v. Invoice numbers in the Invoice worksheet with a voided sales order number in the Sales Order worksheet vi. Sales orders in the Sales Order worksheet with a customer number that is not on the approved customer list c. Summarize your findings. What is your overall conclusion about the occurrence audit objective?