Question 11. A study based on a random sample of 10 U.S. female adults reported a sample mean height of 65 inches with a sample standard deviation of 4 inches.

1. Calculate a 90% Confidence interval for the population mean height of US adult women.
2. What is the margin of error of the 90% confidence interval?
3. Interpret the 90% confidence interval.
4. Suppose you want to plan a study where the margin of error for the true population mean height of adult women is 1 inch. What sample size do you need to achieve the margin of error stated for a 90% confidence interval? Use 4 inches as the true population standard deviation of adult women in the US for planning purposes.
5. What sample size do you need to achieve a 1-inch margin of error for a 95% confidence interval? Use 4 inches as the true population standard deviation of adult women in the US for planning purposes.