利用Γ函数的定义及性质推导卡方分布概率密度函数的表达式、卡方分布的期望与方差,求解一些分布的数字特征,最后介绍Γ函数在概率统计证明中的一些应用.
This paper uses the gamma functions' properties to derive the probability density function,the mathematical expectation expression,and variance of chi-square distributions,and to solve some problems of numerical characteristics of probability distributions.At the end,this paper summarizes the applications of gamma functions in probabilistic and statistical proofs.