Wolfram Technology Guide: Symbolic Statistical Computing  previous | next 
Built-in Statistical Distributions
Mathematica has built-in support for continuous and discrete statistical distributions. This plots the Weibull distribution for several parameter values.
In[1]:=

Click for copyable input
Plot[Evaluate[

  Table[PDF[WeibullDistribution[\[Alpha], 1]][x], {\[Alpha], 5}]], {x,

   0, 2}, Filling -> Axis, Frame -> True]
Out[1]=