You are a revenue agent for the Internal Revenue Service. In November 2014, you audit Dan's 2011 tax return. During the course of the audit, you come to believe that Dan's deductions for business travel and entertainment in 2011 are unsubstantiated, and you propose a $6,000 deficiency assessment for that year. You also examine some prior-year returns. You believe that Dan failed to report $40,000 of gross business income on his 2008 federal tax return. Dan had reported gross income of $60,000 on his 2008 return. You also discover that Dan failed to file a federal tax return in 2005.