一道关于随机变量X的密度函数的题,急~~~
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发布时间:2023-09-25 07:08
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时间:2024-12-13 01:44
f(x) = 0 x<0
1/3 0<=x<1
0 1<=x<3
2/9 3<=x<=6
0 x>6
所以,累计分布函数cdf F(x)= ∫_(-∞<t<=x) f(t) dt
F(x) = 0 x<0
x/3 0<=x<1
1/3 1<=x<3
1/3+(2/9)(x-3) 3<=x<=6
1 x>6
survival function s(x) = P(X>=x) = 1- F(x) = 1 x<0
1-x/3 0<=x<1
2/3 1<=x<3
2/3-(2/9)(x-3) 3<=x<=6
0 x>6
现在,要求P{X>=k}=2/3, 所以,1<=k<=3 。