作者ppman168no1 (杰屎面)
看板Statistics
标题[问题] 一题数统
时间Mon Sep 26 01:13:59 2011
We have seen that if Y has a binomial distribution with parameters n and p,
then Y/n is an unbiased estimator of p.To estimator the variance of Y,we
generally use n(Y/n)(1-Y/n).
a.Show that the suggested estimator is a biased estimator of V(Y).
b.Modify n(Y/n)(1-Y/n) slightly to form an unbiased estimator of V(Y).
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a小题是用E(V(Y))这样算吗??
b小题n(Y/n)(1-Y/n)不就是不偏??怎麽还要更改
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◆ From: 163.24.253.120
※ 编辑: ppman168no1 来自: 163.24.253.120 (09/26 01:19)
1F：→ jodojeda:a. 直接算E(n(Y/n)(1-Y/n)) 09/26 07:25
2F：→ jodojeda:b. 题目没说n(Y/n)(1-Y/n)是不偏 而且a也说他是bias 09/26 07:26
3F：→ jodojeda:所以才需要修正 09/26 07:26
4F：推 goshfju:b. 你要算阿! 我觉得应该是偏误的喔 09/26 11:02
5F：→ yhliu:a小题明明指出那是 biased estimator... 09/26 20:25