11. ADVANCED TOPIC: Christakis and Fowler (2007) studied more than 12,000 people over a 32-year period to examine if people’s chances of becoming obese are related to whether they have friends and family who become obese. They reported that “A person’s chance of becoming obese increased by 57% (95%

confidence interval [CI], 6 to 123) if he or she had a friend who became obese in a given interval” (p. 370). Explain what the 95% confidence interval reported in this study means to a person who understands hypothesis testing with the mean of a sample of more than one, but who has never heard of confidence intervals.