作者NiceKitty (想要有个依靠><)
看板Grad-ProbAsk
标题Re: [商管] [统计学]-西葛马问题
时间Thu Jan 14 21:42:48 2010
locust0923大大说 用三项分配
但是....没听过耶><
※ 引述《NiceKitty (想要有个依靠><)》之铭言：
: 不好意思再请教各位大大一题><
: Consider n independent trials,each of which results in any of the
: outcomes i, i=1,2,3 with respective probabilities P1,p2,p3
: 3
: ΣPi=1.Let Ni denote the number of trials that result in outcome i,
: i=1
: and show that Cov(N1,N2).
: Also explain why it is intuitive that this covariance is negative.
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※ 编辑: NiceKitty 来自: 58.114.107.8 (01/14 21:43)