Adults have blood pressure that is approximately normally distributed. In a study, a blood pressure mean of 113 mmHg with a standard deviation of 13 mmHg was calculated for 50 non-smoking adults. An additional 50 adult smokers were tested and had a mean blood pressure of 124 mmHg and a standard deviation of 14 mm Hg

1. Find the 95% confidence intervals for the population mean for non-smokers and smokers. Show all work.
2. What does this result suggest?
3. Thinking about the 90% confidence interval for the population mean of smokers and non-smokers, what could you tell me without having to perform any calculation when comparing it to the 95% confidence interval calculated above? Why?
4. Find the 95% confidence intervals for the population standard deviation for non-smokers and smokers. Show all work.
5. What does this result suggest?
6. Does this change how you think about your answer to Q6.2? Explain if it does or why it doesn't.