Complete the following steps to specify the data for the power and sample size calculation.
If you enter multiple values into a field, separate the values with a space. You can also use shorthand notation to indicate multiple values. For example, you can enter 10:40/5 to indicate sample sizes from 10 to 40 in increments of 5.
If you select Less than on the Options sub-dialog box, enter a negative difference. Otherwise, enter a positive difference.
Power values: Enter one or more values to specify the probability that the test detects the difference between the means when a difference actually exists. Common values are 0.8 and 0.9. For example, analysts enter 0.9 because they want a 90% chance that the test will detect an important difference between the mean width of dowels and the target width when a difference actually exists.
If you know the standard deviation of the population, use Power and Sample Size for 1-Sample Z because the Z-test has more power than the t-test.