As a fun exercise, take the following little quiz. For your answer to each one, give a 90% confidence level: For example, if the question were "How many teams are in the NHL," a student with no idea might give an answer of 5-40, a student with a good idea might give an answer of 28-32, and so forth. This exercise is intended to get you to think about confidence intervals and understanding the basic idea of what they are all about. It also illuminates the duality of confidence intervals--if you are 90% sure that the correct number is between X and Y, then 90% of all such confidence levels should contain the true value.

Of course many of these questions can easily be googled, but try not to do it. The point here is not to learn about MLK or about the moon, but about confidence intervals. I'll post the answers next Wednesday morning so you check your guesses.

1. What was Martin Luther King, Jr.'s age at death?

2. What is the length of the Nile River, in miles?

3. How many countries belong to OPEC?

4. How many books are there in the Old Testament?

5. What is the diameter of the moon, in miles?

6. What is the weight of an empty Boeing 747, in pounds?

7. In what year was Mozart born?