作者yingigi (...)
看板Statistics
标题Re: [问题] 期望值...
时间Sat Jun 10 04:19:37 2006
※ 引述《stonycindy (Esperanza)》之铭言：
: Question:An automobile repair shop makes an initial estimate X(in thousands)
: need to fix a car after an accident. Say X has the p.d.f.
: f(x)=2e^[-2(x-0.2)] 0.2<x<∞.
: Given X=x, the final payment Y has a uniform distribution between
: x-0.1 and x+0.1. What is the expected value of Y?
: 麻烦请写计算过程!
: 谢谢!
: Answer:E(Y)= x and E(x)=700
令z=x-0.2 , 0<z<∞
f(z)=2e^(-2z) , 0<z<∞ , 所以Z是指数分配
E(Z)=1/2=0.5
E(X)=E(Z)+0.5=0.7
in thousands=700
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