Gamma Distribution

$x$ has a two-parameter gamma distribution, denoted by $Ga(b,c)$, with parameters $b$ and $c$, if its density is given by:

$$f_{Ga}(x;b,c)=\frac{1}{\Gamma(c)}\frac{x^{c-1}}{b^c}e^{-x/b}$$ (36)

where $\Gamma(c)$ is the Gamma function. Note, that a gamma distribution has $mean=bc$ and $variance=b^2c$.