Question

A researcher 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 50​% ​(90% confidence interval​ [CI], 77 to 128​) if he or she had a friend who became obese in a given interval. Explain what the 90​% 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.

Answer 1

Given :

A researcher 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.

90% confidence interval is 77% to 128%

They reported that a​ person's chance of becoming obese increased by 50​% ​

We are 90% confident that true mean is between 77% and 128%

Therefore the confidence interval indicates that there can be 90% confidence that the true mean by which a person's risk of obesity is increased is between 77% and 128%