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Statistics版 - joint distribution
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相关话题的讨论汇总
话题: x2话题: x1话题: x3话题: joint
进入Statistics版参与讨论
1 (共1页)
p********0
发帖数: 186
1
assume X1 is random variable with N(0, 1) and X2 random variable with N(1,2)
What is the distribution for X3=X1+X2?
Is it a mixture model?? f_(X3) = 1/2 f_{X1) + 1/2 f_{X2}
d******e
发帖数: 7844
2
definitely not.
If X1 and X2 are independent, the sum will be N(1,3)
Btw: This is not called joint distribution

2)

【在 p********0 的大作中提到】
: assume X1 is random variable with N(0, 1) and X2 random variable with N(1,2)
: What is the distribution for X3=X1+X2?
: Is it a mixture model?? f_(X3) = 1/2 f_{X1) + 1/2 f_{X2}

p********0
发帖数: 186
3
Thanks, Intuitively the answer is correct? How do you prove it?
Through Pdf or moment generation function?

【在 d******e 的大作中提到】
: definitely not.
: If X1 and X2 are independent, the sum will be N(1,3)
: Btw: This is not called joint distribution
:
: 2)

z*********o
发帖数: 541
4
X3:N(1,3)

2)

【在 p********0 的大作中提到】
: assume X1 is random variable with N(0, 1) and X2 random variable with N(1,2)
: What is the distribution for X3=X1+X2?
: Is it a mixture model?? f_(X3) = 1/2 f_{X1) + 1/2 f_{X2}

z*********o
发帖数: 541
5
it is a theorem. you can try use mgf

【在 p********0 的大作中提到】
: Thanks, Intuitively the answer is correct? How do you prove it?
: Through Pdf or moment generation function?

p********0
发帖数: 186
6
Ding

2)

【在 p********0 的大作中提到】
: assume X1 is random variable with N(0, 1) and X2 random variable with N(1,2)
: What is the distribution for X3=X1+X2?
: Is it a mixture model?? f_(X3) = 1/2 f_{X1) + 1/2 f_{X2}

c**p
发帖数: 204
7
Theory:
X~N(mu1,a1);Y~N(mu2, a2), if independent, then
(X+Y)~ N(mu1+mu2, a1+a2); can extent to n independent ones.

【在 p********0 的大作中提到】
: Thanks, Intuitively the answer is correct? How do you prove it?
: Through Pdf or moment generation function?

N**D
发帖数: 10322
8
google "sum of normal distributions", go to the result in wiki

2)

【在 p********0 的大作中提到】
: assume X1 is random variable with N(0, 1) and X2 random variable with N(1,2)
: What is the distribution for X3=X1+X2?
: Is it a mixture model?? f_(X3) = 1/2 f_{X1) + 1/2 f_{X2}

1 (共1页)
进入Statistics版参与讨论
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HELP needed!! Thank you!!model sample size重要吗?
急问,在线等:SAS adv certification Question about SELECT v.s IF/THEN ELSEtransform to gaussian?
analyze time series data请教一个基础统计问题
工作中用到的factor analysisIn which situation, SELECT is more efficient than IF/THEN
相关话题的讨论汇总
话题: x2话题: x1话题: x3话题: joint