Huxley
Easy calculation of probabilities for the most common distributions (six discrete and nine continuous), fast, intuitive and accurately.
Compare the values of the exact distributions with the usual approximations.
For any set of parameters you will get immediately the most important information about the distribution; expected value, variance, quartiles, and much more.
Graphical representation for the probability function (discrete) or probability density function (continuous) and distribution function also the formulas to assist you with the distributions.