Question 6.41

6.41 In the extremes.

As suggested in our discussions, 90%, 95%, and 99% are probably the most common confidence levels chosen in practice.

  1. In general, what would be a 100% confidence interval for the mean ? Explain why such an interval is of no practical use.
  2. What would be a 0% confidence interval? Explain why it makes sense that the resulting interval provides you with 0% confidence.

6.41

(a) . This is useless because it gives us no information about what is. (b) . The chance that is exactly is has 0 probability, so our confidence is 0%.