[問題] 一題數統

看板Statistics作者 (傑屎面)時間14年前 (2011/09/26 01:14), 編輯推噓1(104)
留言5則, 3人參與, 最新討論串2/3 (看更多)
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). ------------------------------------------------------------------------------ a小題是用E(V(Y))這樣算嗎?? b小題n(Y/n)(1-Y/n)不就是不偏??怎麼還要更改 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 163.24.253.120 ※ 編輯: ppman168no1 來自: 163.24.253.120 (09/26 01:19)

09/26 07:25, , 1F
a. 直接算E(n(Y/n)(1-Y/n))
09/26 07:25, 1F

09/26 07:26, , 2F
b. 題目沒說n(Y/n)(1-Y/n)是不偏 而且a也說他是bias
09/26 07:26, 2F

09/26 07:26, , 3F
所以才需要修正
09/26 07:26, 3F

09/26 11:02, , 4F
b. 你要算阿! 我覺得應該是偏誤的喔
09/26 11:02, 4F

09/26 20:25, , 5F
a小題明明指出那是 biased estimator...
09/26 20:25, 5F
文章代碼(AID): #1EVs5RJk (Statistics)
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文章代碼(AID): #1EVs5RJk (Statistics)