A researcher is analyzing data from a random sample of cigarette smokers older than the age of sixteen. She uses the sample data to estimate the average age of all cigarette smokers. Imagine that the researcher’s confidence interval is the one shown in Figure 8.13.

a. According to Figure 8.13, what is the mean age of smokers in general?

b. What is the mean age of the smokers in the researcher’s sample?

c. What is the value for the bottom of the confidence interval? The top? Does the confidence interval from the researcher’s study include the population mean? How do you know?

d. The researcher writes up the results of her analysis and explains that her estimate of the population mean ranges from 34.5 to 39.5. Is she being dishonest by not reporting that her confidence interval does not include the population mean?