- Click in one of the dark gray margins at either side of the graph to
bring up a "guide line" which you can drag
out across the graph. A shaded area is marked out behind the
guide, and the window displays the probability of the distribution
falling in this area.
- You can draw out a second guide, to mark out two-sided regions.
- Click and drag to move the guide lines once you have laid them out. Drop
a line back in the gray margin area to remove it from the screen.
- The graph of the normal distribution is shown for values of x
between xMax and xMin, which can be changed by typing in the textboxes.
- Initially, figures are given for a distribution with mean 0 and
standard deviation 1. You can changes these values by typing in
the appropriate boxes.
- You can enter numerical values for the guide positions by clicking the
"Set range..." button. Enter the values of the probability range in the
fields of the pop-up panel, and click the OK button (the green check) or
dismiss the panel with the Cancel button (the red cross).