1. As the level of confidence increases, what happens to the width of the confidence interval? Does it increase or decrease? Explain one reason why this would happen.
2. Using the 95% confidence interval, compare the BMI of smokers vs. nonsmokers. Write a few sentence paragraph explaining whether these intervals overlap or not. What does that indicate about the differences in BMI between the two groups?
3. In a few sentences, explain the following: What is one situation in which you as a researcher might choose a 99% confidence interval? A 90% interval? Fully justify your choices.

Group		90% confidence interval	95% confidence interval	99% confidence interval
Smokers	Mean = 28 Standard Deviation = 5.366
Nonsmokers	Mean = 29.1 Standard Deviation = 6.042