作者maxmie (王小Ming)
看板Statistics
标题[问题] PDF 问题
时间Tue Oct 18 23:30:14 2016
不好意思 打扰各位先进了
小弟最近在学统计
在P.D.F的例题上碰到了一些问题 脑筋有点转不过来..
概念也需要高手指导..
所以有三道题目想请问大家该如何解
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?
以上三题 麻烦求解..
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1F：推 ases60909: pdf 的基本性质 10/22 17:19
2F：→ ases60909: 1.f(x)>=0 10/22 17:19
3F：→ ases60909: 2.积分(-inf 到 inf)f(x) dx=1 10/22 17:19