With this applet, you can calculate the chi-square statistic for a simple table and then simulate the chi-square statistic to estimate the P-Value. Below the "observed" and "expected" columns, fill in the observed and expected counts with your own data, and then press "OK." The chi-square statistic will appear at the bottom of the screen. You can also examine the distribution of the chi-square statistic by performing simulations. Enter the following data under the "observed" column: 14, 18, 20, 20, 15, 34, 20, 24, 25, and 10. Under the "expected" column enter 20 in each of the 10 cells. Click "OK." In the top center of the window (yellow area), click 100 simulations. What percent exceeds the chi-square?

This tutorial and demonstration explains the basics of chi-square. Use the first applet to enter the data from the table in the tutorial (also shown below) and calculate chi-square. Compare the computed chi-square to that shown in the computation. What is the critical value of chi-square? Is the computed value significant with alpha level set at .05?

Treated/Dead 36

Treated/Alive 14

Not Treated/Dead 30

Not Treated/Alive 50