A Chi-square calculator for 2-6 samples

The program is here

Use this calculator for running a Chi-square analysis for 2-6 treatments. The null hypothesis is that the distribution (in this case, fruit fly mutants) is not different from the expected values. Start the Chi-square program.

There are 4 treatments (enter 4 in the first box). The data entry boxes open for 4 treatments. Follow with the expected distribution (in this case, 9:3:3:1; you could also enter this as frequencies: 0.562:0.187:0187:0.062, although the first form is easier).

Enter the observed values (90,35,27,3). You can't enter anything in the "expected value" boxes (that will be calculated). Press the "Do it!" button.

The Chi-square is calculated (Chi2 = 6.013, with 3 degrees of freedom). A table opens up and the magic glove points to the proper row. Since 6.013 is less than 7.82, we accept the null hypothesis that the observed data fit a 9:3:3:1 ratio. If you want to test a different number of treatment groups, click the reset button. If you want to test a different data set with the same number of treatments, just enter the data (you can write of the expected frequencies if different from the original 9:3:3:1 ratio)