This test is used to test a claim about the mean of a single population, such as this claim: "The mean IQ of statistics students is greater than 100."
First select the format of the original claim that is to be tested. Note that there are 6 different choices, which can be viewed by clicking on the small box to the right of the default claim ("Pop. Mean = Claimed Mean"). 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.
Claimed Mean: Enter the value of the mean used in the original claim.
Population StDev: Enter a value for the population standard deviation only if it is known (otherwise, leave this box blank). In reality, this value is usually not known, so this box is usually left blank. DO NOT ENTER THE VALUE OF THE SAMPLE STANDARD DEVIATION HERE.
Enter the sample size as a positive whole number.
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.