INSTRUCTIONS
Once the applet has finished loading, a "Lab-value" buttonwill appear
on the screen. This may take a minute or two depending on the speed of
your internet connection and computer. Please be patient. If no begin button
appears, it is probably because your browser does not support Java 1.1.
The Chi-square statistic is used for making inferences on the value of the variance sigma square of a normal population. If the null hypothesis is Ho: sigma square = sigmao square , then the Chi-square test statistic
Chi-square = (n-1)s square/sigmao square
has a Chi-square (n-1) distribution.
There will be a table show the comparation from the percentiles of the theoretical normal distribution to the histogram. The first column of numbers (which includes 2.5, 5.0..., 97.5) are areas to the left of the numbers in the second column for the theoretical(standard Chi-square (n-1)) distribution. The third column of numbers are percentiles from the histogram. The numbers in the fourth column are the areas from the histogram to the left of the percentiles in the second column.