[問題] PDF 問題

看板Statistics作者 (王小Ming)時間7年前 (2016/10/18 23:30), 編輯推噓1(102)
留言3則, 1人參與, 最新討論串1/1
不好意思 打擾各位先進了 小弟最近在學統計 在P.D.F的例題上碰到了一些問題 腦筋有點轉不過來.. 概念也需要高手指導.. 所以有三道題目想請問大家該如何解 1. Consider the continuous probability density function given by Px(x)=0.25 for 0<x<a (a)what is a? (b)what is prod(x>a/2) (c)what is prob (X>a/2|X>a/4) (d)what is prob(X>a/2|X<a/4) 2.Assume that the probability density function of daily rainfall is given by prob(X=0) = 0.25 X=0 Px(x)=0.25x 0<X<1.732 Px(x)=0.866-0.25x 1.732<X<3.464 (a)Is this a proper probability density function? (b)what is prob(X>0.5)? (c)What is prob(X>0.5|X≠0)? 3.Consider the probability density function given by Px(x)=(λ1)/2 0<X<2 Px(x)=(1-λ1)/4 2<X<6 (a)Sketch px(x) for λ1 = 0.5 (b)Sketch px(x) for λ1 = 0.1 (c)Sketch px(x) for λ1 = 0.333 (d)In a random sample from px(x),60% of the values were between 0 and 2. What would be an estimate for the value of λ1? 以上三題 麻煩求解.. -- ※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 220.141.162.113 ※ 文章網址: https://www.ptt.cc/bbs/Statistics/M.1476804617.A.529.html

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pdf 的基本性質
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1.f(x)>=0
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2.積分(-inf 到 inf)f(x) dx=1
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文章代碼(AID): #1O1a09Kf (Statistics)