The expectation of a geometric random variable where its parameter is uniform











up vote
1
down vote

favorite












First thanks for any help editing my text.



If a random variable $X$ has a geometric distribution with parameter $P$ where $P$ itself is a random variable and uniformly distributed from $0$ to $1-1/n$, I want to find $E[X]$.



I first learned that $E[X|P] = 1/P$, using the expectation of the geometric distribution.



But when it comes to $E[X]=E[E[X|P]]$, I tried integration and it seems to be



(integral from $0$ to $(n-1)/n$) , $(1/p)$ * $(n/(n-1))$ $dp$



but isn't the value infinite?










share|cite|improve this question
























  • I think you are right.
    – Kavi Rama Murthy
    Nov 19 at 7:45










  • Yes; were you expecting it to be finite or any particular reason?
    – Aditya Dua
    Nov 20 at 7:15















up vote
1
down vote

favorite












First thanks for any help editing my text.



If a random variable $X$ has a geometric distribution with parameter $P$ where $P$ itself is a random variable and uniformly distributed from $0$ to $1-1/n$, I want to find $E[X]$.



I first learned that $E[X|P] = 1/P$, using the expectation of the geometric distribution.



But when it comes to $E[X]=E[E[X|P]]$, I tried integration and it seems to be



(integral from $0$ to $(n-1)/n$) , $(1/p)$ * $(n/(n-1))$ $dp$



but isn't the value infinite?










share|cite|improve this question
























  • I think you are right.
    – Kavi Rama Murthy
    Nov 19 at 7:45










  • Yes; were you expecting it to be finite or any particular reason?
    – Aditya Dua
    Nov 20 at 7:15













up vote
1
down vote

favorite









up vote
1
down vote

favorite











First thanks for any help editing my text.



If a random variable $X$ has a geometric distribution with parameter $P$ where $P$ itself is a random variable and uniformly distributed from $0$ to $1-1/n$, I want to find $E[X]$.



I first learned that $E[X|P] = 1/P$, using the expectation of the geometric distribution.



But when it comes to $E[X]=E[E[X|P]]$, I tried integration and it seems to be



(integral from $0$ to $(n-1)/n$) , $(1/p)$ * $(n/(n-1))$ $dp$



but isn't the value infinite?










share|cite|improve this question















First thanks for any help editing my text.



If a random variable $X$ has a geometric distribution with parameter $P$ where $P$ itself is a random variable and uniformly distributed from $0$ to $1-1/n$, I want to find $E[X]$.



I first learned that $E[X|P] = 1/P$, using the expectation of the geometric distribution.



But when it comes to $E[X]=E[E[X|P]]$, I tried integration and it seems to be



(integral from $0$ to $(n-1)/n$) , $(1/p)$ * $(n/(n-1))$ $dp$



but isn't the value infinite?







probability-distributions conditional-expectation uniform-distribution expected-value






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 19 at 8:03

























asked Nov 19 at 7:40









Richard

426




426












  • I think you are right.
    – Kavi Rama Murthy
    Nov 19 at 7:45










  • Yes; were you expecting it to be finite or any particular reason?
    – Aditya Dua
    Nov 20 at 7:15


















  • I think you are right.
    – Kavi Rama Murthy
    Nov 19 at 7:45










  • Yes; were you expecting it to be finite or any particular reason?
    – Aditya Dua
    Nov 20 at 7:15
















I think you are right.
– Kavi Rama Murthy
Nov 19 at 7:45




I think you are right.
– Kavi Rama Murthy
Nov 19 at 7:45












Yes; were you expecting it to be finite or any particular reason?
– Aditya Dua
Nov 20 at 7:15




Yes; were you expecting it to be finite or any particular reason?
– Aditya Dua
Nov 20 at 7:15















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',
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%2f3004623%2fthe-expectation-of-a-geometric-random-variable-where-its-parameter-is-uniform%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown






























active

oldest

votes













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.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • 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.


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%2f3004623%2fthe-expectation-of-a-geometric-random-variable-where-its-parameter-is-uniform%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

Biblatex bibliography style without URLs when DOI exists (in Overleaf with Zotero bibliography)

ComboBox Display Member on multiple fields

Is it possible to collect Nectar points via Trainline?