Chapter 7.3, Problem 1AC

Contracting Influenza

To answer the questions, use the following table describing the percentage of people who reported contracting influenza by gender and race/ethnicity.

Forty-nine states and the District of Columbia participated in the study. Weighted means were used. The sample size was 19,774. There were 12,774 women and 7000 men.

1. Explain what (95% CI) means.

2. How large is the margin of error for men reporting influenza?

3. What is the sample size?

4. How does the sample size affect the size of the confidence interval?

5. Would the confidence intervals be larger or smaller for a 90% CI, using the same data?

6. Where does the 51.5% influenza for women fit into its associated 95% CI?