This test is used to test a claim about two different population standard deviations (or variances), such as this claim: "IQ scores of males have a standard deviation equal to the standard deviation of the IQ scores of females."
First select the format of the original claim that is to be tested. Note that there are 6different choices, which can be viewed by clicking on the small box to the right of the default claim ("Pop. StDev 1= Pop. StDev 2"). Use the up/down arrow keys to highlight the desired choice, then click on that desired choice. STATDISK will determine the appropriate null hypothesis from the claim selected.
Significance (level): Enter a positive value in decimal form, such as 0.05.
For Sample 1, make these entries:
For Sample 2, make the corresponding entries as described above.
Click on the Evaluate button to obtain the results.
Click on the Print button to print the results.
Click on the Plot button to display a graph showing the distribution with the test statistic and critical value(s).
To close the window, click on the X at the top of the module window.