This interactive lesson is designed to demonstrate the basic concept of Power. To operate this application go into the edit boxes for Sigma, Research Mean, and Sample Size and change them to desired values. You can not edit either the Power or Beta edit boxes.

All values must be of integer value. The acceptable range for Sigma is 15 to 30; for the Research Mean the values 100 to 120 are valid; and for Sample Size the values 35 to 55 are valid. After making changes to the various edit boxes, hit "Refresh" to redraw the picture with the current values. If you enter invalid data either because it was out of range or not an integer, the picture will be redrawn with the old value instead of updates. To reset the screen hit the "Reset" button at the bottom of the page.

Please note that the Null Curve is centered at 100 and both Power and Beta are calculated assuming a 5% alpha level. To print the results click on the "PRINT" button provided by the browser. To exit the page click on "BACK" button provided by the browser.