Merge pull request #3434 from chang111/fix-documentation-on-weibull-distribution

Fix the documentation on Weibull distribution

Author: lucianopaz

pymc3/distributions/continuous.py

@@ -2624,7 +2624,7 @@ class Weibull(PositiveContinuous):
     ========  ====================================================
     Support   :math:`x \in [0, \infty)`
     Mean      :math:`\beta \Gamma(1 + \frac{1}{\alpha})`
-    Variance  :math:`\beta^2 \Gamma(1 + \frac{2}{\alpha} - \mu^2)`
+    Variance  :math:`\beta^2 \Gamma(1 + \frac{2}{\alpha} - \mu^2/\beta^2)`
     ========  ====================================================
 
     Parameters