[商管] [統計]-區間估計
A researcher has reason to believe that,for an experiment
with 50 points,a 95% prediction interval would be of width 8.
If the researcher wishes to run a more precise experiment
that will result in a 95% prediction interval of width 4 ,
then the researcher will require how many points?
我的解法如下
2E=8 E=4
Z(0.025)‧(σ^2‧(1+ 1/50))^(0.5) = 4
求解出σ^2 = 4.0833
然後 區間要縮到4 2E=4 E=2
Z(0.025)‧(4.0833‧(1+ 1/n))^(0.5) =2
解出 n 竟然是負數 n = -2.1052
然後總結 回答 在95%信心水準下 無論如何增加樣本數
皆無法使信賴區間寬度縮小到 4
請問這樣對嗎? THX
P.S.題目沒抄錯 (或許題目出錯?)
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03/01 21:30, , 1F
03/01 21:30, 1F
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