More than 3,000 Americans quit smoking each day. Because nicotine is one of the most addictive drugs, quitting smoking is a difficult and frustrating task. It usually takes several tries before success is achieved. There are various methods, including cold turkey, nicotine patch, hypnosis, and group therapy sessions. In an experiment to determine how these methods differ, a random sample of smokers who have decided to quit is selected. Each smoker has chosen one of the methods listed above. After one year, the respondents report whether they have quit (1 = Yes, 2 = No) and which method they used (1 = Cold turkey, 2 = Nicotine patch, 3 = Hypnosis, 4 = Group therapy sessions). Is there sufficient evidence to conclude that the four methods differ in their success?