给出了负二项分布的两个不同定义与一个结构性定理.研究了两类负二项随机变量的无穷可分性.给出了求两类负二项随机变量的期望、方差与矩母函数的几种简捷方法.另外给出了涉及负二项随机变量的两个计算实例.
Two different definitions of the negative binomial distributions were intro- duced and a structural theorem was presented for the negative binomial random varia- bles. The infinite divisibility of two types of the negative binomial random variables was investigated. Also several simple calculating methods for calculating the expectations, variances and moment generating functions of these random variables were given. And two illustrative calculating examples were shown as well.