Confidence Interval for a Mean

To use the applet below, just type in the information into the boxes.  Hit enter when you are finished typing.  You will need a calculator to work these problems out.  You may assume that the given standard deviation is equal to the population standard deviation.  This assumption will allow you to use the table below.

Table for Confidence Intervals

c 0.8 0.9 0.95 0.99
zc 1.28 1.645 1.96 2.58



Written Exercises

When you have mastered the above tutorial, please answer the following in a few complete sentences

  1. What are the steps for determining a confidence interval for a mean?

  2. If a 99% confidence interval for the mean is [3,5], is it possible for the true mean to be 6?



Information on finding the confidence interval for a mean

Statistics Lecture Notes

Back to Larry Green's Java Applets