设<img src="https://static.zxtiku.com/wangke/imgs/topic/d266516d0e1b17afa83f8a23651ec59a.jpg"/>的分布律为<img src="https://static.zxtiku.com/wangke/imgs/topic/029f32ad3e22553e6c815ab3a26aadf7.jpg"/><br/> 则参数<img src="https://static.zxtiku.com/wangke/imgs/topic/1cfa51d09d87b80dc669774c57ce2506.jpg"/>=