You have been assigned to perform tests of controls on the sales system at Auto Parts Inc., as part of the December 31, 2020 audit.

Auto Parts Inc. is a wholesaler that sells replacement auto parts to automobile dealers in Canada.

During the testing, you noticed the following errors:

1. 1. Invoice # 54922 issued on January 12, 2020 was entered twice. The error was discovered when the customer phoned to complain about being charged double on the agreed amount.
2. 2. Invoice no. 51839 issued on March 25, 2020 contained incorrect prices. Three vanity mirrors were charged at $453 each instead of $543, and five silver gas pedals were charged at $231 each instead of $321. The error was discovered when Auto Parts Inc.s salesperson complained that, because of the pricing error, she did not receive the proper commission on the sale.
3. 3. No prices were entered on invoice # 56329 issued on April 15, 2020. Resulting in a zero dollar invoice being issued. The error was discovered when the accounts receivable clerk noticed the zero amount appearing on the accounts receivable ledger.

Invoice # 59328 issued on June 27, 2020, matched the customers order. However, the order was only partially filled because of a lack of inventory in the warehouse, meaning items that were never delivered were included in the invoice. The inventory that was not delivered should have been backordered rather than invoiced. The error was discovered when the customer phoned to complain about being over charged