Estimating Confidence Intervals
For each of the following questions, answer in terms of a range, rather than a single number. Specifically, you should supply a 98% confidence interval. A confidence interval is the range within which you expect the correct answer to fall. For example, suppose you answer a question by supplying a 98% confidence interval that is 2,000 to 7,000. This means that you think there is only a 2% chance that the real answer is either less than 2,000 or more than 7,000. The correct answers can be found at the end of the chapter on page 452.
1. How many full-time students were enrolled in U.S. colleges and universities in 2011?
2. According to the official count, how many people died in the 2011 earthquake and tsunami in Japan?
3. In what year did Martin Van Buren begin his term as the president of the
United States?
4. In 2009, what was the average life expectancy in Canada?
5. How many dollars did the United States spend for military expenditures in 2010?
6. In what year did New Zealand give women the right to vote?
7. What was the median salary of a U.S. male college graduate in 2009?
8. What is the total area of Canada (in either square kilometers or square miles)?
9. What was the estimated population of France in 2010?
10. Of the residents of Canada, what percentage report that they are Roman Catholics?
