Re: [商管] [統計]-台大-統計D

看板Grad-ProbAsk作者urml (!#(狗VioL>DoGGiE)時間16年前 (2010/02/25 23:37)推噓2(2推 0噓 9→)

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※ 引述《ONIspirit (嘎)》之銘言： : 1. : _ : Let x be the sample mean of a random sample of size 16 from N(2,4), and : _ : let y be the sample mean of another random sample of size 4 from the : same parent population : _ _ : Q. Find the probability P(x - y > 0 ) _ _ x ~ N (2, 4/16) y ~ N(2, 4/4) _ _ x - y ~ N(0, 4/16 + 4/4) => P(Z>0) = 0.5 : 2. : An anumal ecologist suggests three methods to prevent squirrels : from damaging Cryptomeria plantations. To determine the effectiveness : of the three methods, a small experiment was conducted with 9 replications : for each treatment(method). : Mean square error(MSE) of the experiment is 60. : Please 1) state an appropriate model and its assumptions : 2) construct a complete ANOVA table based on the given information : and state your conclusions. Let the a = 0.05 . : 　　　　　　　 ──────── : 　　　　　　　 Method : 　　　　　　　 _______________ : 　 : 　　　　　　 I II III : Treatment Total 243 324 189 1) iid Ⅹij = μ+αi+εij εij ~ N(0, σ^2) 2) H0: the effectiveness of the three methods doesn't have sig. diff vs H1: the effectiveness of the three methods have sig. diff df(SST) = 9*3-1 =26 df(SSR) = 2 df(SSE) = 26-2 =24 SSE = 24*60 = 1440 SSR = (243^2+324^2+189^2)/9 - [(243+324+189)^2]/27 =22194 - 21168=1026 SST = SSE + SSR = 2466 SS df MS F Sig SSR 1026 2 513 8.55>F(.05,2,24) = 3.403 yes SSE 1440 24 60 SST 2466 26 the effectiveness of the three methods have sig. diff at α=.05 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 123.195.32.195

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