An audit of the inventory records of Mulder Inc. identified a number of errors over the past six years involving ending inventory. These errors are summarized in Exhibit A below:

Year Net Income Description of Error As Reported in Ending Inventory Amount 2015 $50,000 Overstatement $5,000 2016 $52,000 Overstatement $9,000 2017 $54,000 Understatement $11,000 2018 $56,000 No error 2019 $58,000 Understatement $2,000 2020 $60,000 Overstatement $10,000