If you do not see an applet here, chances are that you are using Netscape with Mac OS. Not to worry you are only 8 clicks away from viewing this applet.

1. Please download the Apple Runtime for Java available for FREE at (if you already have the Apple Applet Viewer, skip to step 5):


2. Once the program has downloaded, click on the the MRJ2.2.2.smi icon on your desktop.

3. Click on the MRJ Install icon to install the applet viewer.

4. Open the Apple Applet Runner Folder

5. Click on the Apple Applet Runner Icon

6. In the file menu select Open location

5. Copy the URL of this page and paste it into the Location box of the Applet Runner window.

6. Click Open. The applet may take a moment or two to load.

It will be worth your time, I promise!

NOTE: You can also save the applet in your Apple Applet Viewer Favorites if you want to access it more quickly next time. Do the following:

When the applet is loaded, go to the applets menu and select add applet to list.

Statistics: Chi-Square Test

The chi-square test is employed when one whishes to determine if a sample fits some theoretical distribution. The chi-square statistic is calculated as:

where are the observed, and are the expected counts.

Once calculated, the chi-square statistic is compared to a critical value, which is determined using the sample size, the chosen level of significance (typically a = 0.05), and a critical value table. If the statistic calculated is less than the critical value, the sample fits the theoretical distribution. Otherwise, there is a significant difference between the observed and expected.

Statistics: Chi-Square Test

Adjust the observed and expected counts to the right:

In this case the critical value doesn't change because the sample size remains constant.