# Probability and Quantile Applets

I've created JAVA code for handling most of the routine things
with common distributions, such as computing probabilities, quantiles,
and generating random variates. I have written most of these things as
Literate Programs in Noweb and I will make
them available to the public very soon.

Although, the same thing is easily done for all the implemented
distributions, only two applets that can be used to calculate
probabilities under the normal curve and quantiles of normal
distribution are presented.

## Probability Applet

The first applet below calculates areas under the standard normal
density curves. You are presented with two fields and three buttons
on top of a normal density curve. The buttons allow you to calculate
areas to the left or to the right or between.

- For areas to the left, use the left data entry field.
- For areas to the right, use the right data entry field.
- For areas between two points, use both fields.

The interface is quite forgiving. If you mess up, it takes you right
to the field where you have to type.

## Quantile Applet

The second applet calculates quantiles of the normal
distribution. You can choose any mean and any standard deviation. The
applet will return the requested quantile.

Invalid input is ignored. You are just taken back to the offending
field to try again.

Last modified: Sun Jul 21 23:18:18 PDT 1996