Areas Under the Normal Distribution
(x and z-values)

How to Use this Applet

The Graph Area

  • Drag any highlighted location (or any rectangle pointing to a highlighted location) on the z-axis to move that location along the z-axis.
  • The <LEFT> and <RIGHT> arrow keys can be used to horizontally move the location with indicator arrows.
  • The <UP> and <DOWN> arrow keys can be used to switch the indicator arrows from one highlighted location to the other.
  • If the arrow keys don't respond, click the cursor in the applet frame then try again.


  • Use the DECONSTRUCT button to see how the area is calculated using areas generated from tables [ A( z ≤ n ), -3.49 < n < 3.49, n rounded to the hundredths position ].
  • Use the other buttons to set the mean, standard deviation, individual x-values and corresponding z-values.