Probabilities for the Normal Distribution 
Return to Seeing Statistics Normal Probability Examples  
HowTo: Enter beginning and ending zscores in the Start and End boxes. The figure is redrawn and the new probability is calculated after hitting the return key while the cursor is in one of the boxes. For openended ranges (i.e., finding the proportion of observations that will lie below a given value or above a given value), use a very large number for the other end (10 is large in this context). 

Change the numbers in the Mean and StDev boxes as appropriate
and then enter the appropriate Start and End values.
Remember to hit the Return key in the last box
you enter to start the calculations and redrawing.

Return to Seeing Statistics Normal Probability Examples 
WARNING: The graph above gives accurate normal probabilities suitable for educational purposes such as homework problems. It is not intended for and should not be used for any calculations which have any major consquences for health, safety, financial matters, etc.
The above applet is from the section "Working with the Normal Distribution" in Seeing Statistics by Gary McClelland. For more information, visit Seeing Statistics
© 1999, Duxbury Press