Exercises


1. What percent of the 95% confidence intervals would you expect to contain 50?
2. Which is wider, 95% or 99% confidence intervals? Why?
3. How does sample size affect the number of intervals that contain 50? Explain.
4. How does sample size affect the width of the intervals?
5. The widths of the intervals vary somewhat even for a given sample size. Why?
6. Is there a tendency for intervals not containing 50 to differ in length from those that do? If so, why?
7. If you already knew that the population mean were 50, what value would there be in computing a confidence interval?
8. There is an important determinant of the width of confidence intervals that you cannot modify in this simulation. What is it?