توزیع دریکله عمومی

اگر ${\displaystyle X=\left(X_{1},\ldots ,X_{k}\right)\sim GD_{k}\left(\alpha _{1},\ldots ,\alpha _{k};\beta _{1},\ldots ,\beta _{k}\right)}$ آنگاه

${\displaystyle E\left[X_{1}^{r_{1}}X_{2}^{r_{2}}\cdots X_{k}^{r_{k}}\right]=\prod _{j=1}^{k}{\frac {\Gamma \left(\alpha _{j}+\beta _{j}\right)\Gamma \left(\alpha _{j}+r_{j}\right)\Gamma \left(\beta _{j}+\delta _{j}\right)}{\Gamma \left(\alpha _{j}\right)\Gamma \left(\beta _{j}\right)\Gamma \left(\alpha _{j}+\beta _{j}+r_{j}+\delta _{j}\right)}}}$

که ${\displaystyle \delta _{j}=r_{j+1}+r_{j+2}+\cdots +r_{k}}$. بنابراین

${\displaystyle E\left(X_{j}\right)={\frac {\alpha _{j}}{\alpha _{j}+\beta _{j}}}\prod _{m=1}^{j-1}{\frac {\beta _{m}}{\alpha _{m}+\beta _{m}}}.}$

1. https://web.archive.org/web/20081119000022/http://www.nscb.gov.ph/ncs/9thncs/papers/theory_Generalization.pdf