Conditional distribution between jointly normal and univariate normal random variables












0












$begingroup$


Let $X = (X_1, X_2, X_3)^Tsim N_3(mu, Sigma)$, where



$$mu = begin{pmatrix}
1 \
1 \
1 \
end{pmatrix}, Sigma = begin{pmatrix}
1 & 1 & 0 \
1 & 2 & 1 \
0 & 1 & 2 \
end{pmatrix} $$



I want to find $(X_1, X_2)^T|X_3$.



I know that $(X_1, X_2)^T sim N_2(begin{pmatrix}
1\
1 \
end{pmatrix}, begin{pmatrix}
1 & 1 \
1 & 2 \
end{pmatrix})$
and that $X_3 sim N_1(1, 2)$.



My definition of conditional distribution of MVN however initially requires the distribution of $((X_1, X_2)^T, X_3)$, of which I am not sure.



Is there another way around this that I am missing? Thanks for your help.










share|cite|improve this question









$endgroup$












  • $begingroup$
    Cross posted at stats.stackexchange.com/q/384280/119261.
    $endgroup$
    – StubbornAtom
    Dec 24 '18 at 5:51
















0












$begingroup$


Let $X = (X_1, X_2, X_3)^Tsim N_3(mu, Sigma)$, where



$$mu = begin{pmatrix}
1 \
1 \
1 \
end{pmatrix}, Sigma = begin{pmatrix}
1 & 1 & 0 \
1 & 2 & 1 \
0 & 1 & 2 \
end{pmatrix} $$



I want to find $(X_1, X_2)^T|X_3$.



I know that $(X_1, X_2)^T sim N_2(begin{pmatrix}
1\
1 \
end{pmatrix}, begin{pmatrix}
1 & 1 \
1 & 2 \
end{pmatrix})$
and that $X_3 sim N_1(1, 2)$.



My definition of conditional distribution of MVN however initially requires the distribution of $((X_1, X_2)^T, X_3)$, of which I am not sure.



Is there another way around this that I am missing? Thanks for your help.










share|cite|improve this question









$endgroup$












  • $begingroup$
    Cross posted at stats.stackexchange.com/q/384280/119261.
    $endgroup$
    – StubbornAtom
    Dec 24 '18 at 5:51














0












0








0


0



$begingroup$


Let $X = (X_1, X_2, X_3)^Tsim N_3(mu, Sigma)$, where



$$mu = begin{pmatrix}
1 \
1 \
1 \
end{pmatrix}, Sigma = begin{pmatrix}
1 & 1 & 0 \
1 & 2 & 1 \
0 & 1 & 2 \
end{pmatrix} $$



I want to find $(X_1, X_2)^T|X_3$.



I know that $(X_1, X_2)^T sim N_2(begin{pmatrix}
1\
1 \
end{pmatrix}, begin{pmatrix}
1 & 1 \
1 & 2 \
end{pmatrix})$
and that $X_3 sim N_1(1, 2)$.



My definition of conditional distribution of MVN however initially requires the distribution of $((X_1, X_2)^T, X_3)$, of which I am not sure.



Is there another way around this that I am missing? Thanks for your help.










share|cite|improve this question









$endgroup$




Let $X = (X_1, X_2, X_3)^Tsim N_3(mu, Sigma)$, where



$$mu = begin{pmatrix}
1 \
1 \
1 \
end{pmatrix}, Sigma = begin{pmatrix}
1 & 1 & 0 \
1 & 2 & 1 \
0 & 1 & 2 \
end{pmatrix} $$



I want to find $(X_1, X_2)^T|X_3$.



I know that $(X_1, X_2)^T sim N_2(begin{pmatrix}
1\
1 \
end{pmatrix}, begin{pmatrix}
1 & 1 \
1 & 2 \
end{pmatrix})$
and that $X_3 sim N_1(1, 2)$.



My definition of conditional distribution of MVN however initially requires the distribution of $((X_1, X_2)^T, X_3)$, of which I am not sure.



Is there another way around this that I am missing? Thanks for your help.







probability-distributions random-variables normal-distribution conditional-probability






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 23 '18 at 12:23









JasonJason

82




82












  • $begingroup$
    Cross posted at stats.stackexchange.com/q/384280/119261.
    $endgroup$
    – StubbornAtom
    Dec 24 '18 at 5:51


















  • $begingroup$
    Cross posted at stats.stackexchange.com/q/384280/119261.
    $endgroup$
    – StubbornAtom
    Dec 24 '18 at 5:51
















$begingroup$
Cross posted at stats.stackexchange.com/q/384280/119261.
$endgroup$
– StubbornAtom
Dec 24 '18 at 5:51




$begingroup$
Cross posted at stats.stackexchange.com/q/384280/119261.
$endgroup$
– StubbornAtom
Dec 24 '18 at 5:51










0






active

oldest

votes












Your Answer





StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3050302%2fconditional-distribution-between-jointly-normal-and-univariate-normal-random-var%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Mathematics Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3050302%2fconditional-distribution-between-jointly-normal-and-univariate-normal-random-var%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

Bundesstraße 106

Verónica Boquete

Ida-Boy-Ed-Garten