module for calculating some values of common statistical distributions

 Statistics::Distributions calculates percentage points (5 significant digits)
 of the u (standard normal) distribution, the student's t distribution, the
 chi-square distribution and the F distribution. It can also calculate the upper
 probability (5 significant digits) of the u (standard normal), the
 chi-square, the t and the F distribution. These critical values are needed to
 perform statistical tests, like the u test, the t test, the F test and the
 chi-squared test, and to calculate confidence intervals.
 .
 If you are interested in more precise algorithms you could look at:
 .
 StatLib: http://lib.stat.cmu.edu/apstat/ ;
 .
 Applied Statistics Algorithms by Griffiths, P. and Hill, I.D., Ellis Horwood:
 Chichester (1985)