People over the age of 40 years tend to notice changes in their digestive systems that alter what and how much they can eat. A study was conducted to see whether this observation applies across different ethnic segments of our society. Random samples of Anglo- Saxons, Germans, Latin Americans, Italians, Spaniards, and African Americans were obtained. The data from this survey are summarized here:
a. Does it appear that there may be a bias due to the response rates?
b. Compare the rates (πis) for the Anglo- Saxon and German groups using a 95% confidence interval.