System of two electronic devices in parallel, with conditional lifetimes.












0












$begingroup$


Suppose we have a system made up of two elements in parallel. I know that their lifetime, conditioned to $Theta = lambda$, are independent exponential with parameters respectively $lambda$ and $2lambda$. The density of $Theta$ is an exponential of parameter 1.



I want to calculate the probability that the system lasts for at least a time t.



Below is what I have done, I feel I am very close to the solution but I cannot work out where to integrate.



Let $T_1$ and $T_2$ be the lifetimes of the two devices.
By properties of conditional probability, I can write this:



$$max(T_1,T_2) = [max(T_1,T_2)vert lambda] *f(lambda)$$



Where $max(T_1,T_2)$ would be the joint density function.



Now I feel like I can write this:



$$mathbb{P}[max(T_1,T_2)>t] = int_?^?mathbb{P}[max(T_1,T_2)>tvert lambda] f(lambda)dlambda$$



However I am not sure what to put instead of the two ?.



Could you shed some light on that?










share|cite|improve this question











$endgroup$












  • $begingroup$
    In general the integration limits is $-infty$ and $infty$. In your case since $Theta$ is exponential, the support is $(0, infty)$, so you can replace with that. (i.e. $f(lambda) = 0$ when $lambda leq 0$.)
    $endgroup$
    – BGM
    Jan 7 at 10:10
















0












$begingroup$


Suppose we have a system made up of two elements in parallel. I know that their lifetime, conditioned to $Theta = lambda$, are independent exponential with parameters respectively $lambda$ and $2lambda$. The density of $Theta$ is an exponential of parameter 1.



I want to calculate the probability that the system lasts for at least a time t.



Below is what I have done, I feel I am very close to the solution but I cannot work out where to integrate.



Let $T_1$ and $T_2$ be the lifetimes of the two devices.
By properties of conditional probability, I can write this:



$$max(T_1,T_2) = [max(T_1,T_2)vert lambda] *f(lambda)$$



Where $max(T_1,T_2)$ would be the joint density function.



Now I feel like I can write this:



$$mathbb{P}[max(T_1,T_2)>t] = int_?^?mathbb{P}[max(T_1,T_2)>tvert lambda] f(lambda)dlambda$$



However I am not sure what to put instead of the two ?.



Could you shed some light on that?










share|cite|improve this question











$endgroup$












  • $begingroup$
    In general the integration limits is $-infty$ and $infty$. In your case since $Theta$ is exponential, the support is $(0, infty)$, so you can replace with that. (i.e. $f(lambda) = 0$ when $lambda leq 0$.)
    $endgroup$
    – BGM
    Jan 7 at 10:10














0












0








0





$begingroup$


Suppose we have a system made up of two elements in parallel. I know that their lifetime, conditioned to $Theta = lambda$, are independent exponential with parameters respectively $lambda$ and $2lambda$. The density of $Theta$ is an exponential of parameter 1.



I want to calculate the probability that the system lasts for at least a time t.



Below is what I have done, I feel I am very close to the solution but I cannot work out where to integrate.



Let $T_1$ and $T_2$ be the lifetimes of the two devices.
By properties of conditional probability, I can write this:



$$max(T_1,T_2) = [max(T_1,T_2)vert lambda] *f(lambda)$$



Where $max(T_1,T_2)$ would be the joint density function.



Now I feel like I can write this:



$$mathbb{P}[max(T_1,T_2)>t] = int_?^?mathbb{P}[max(T_1,T_2)>tvert lambda] f(lambda)dlambda$$



However I am not sure what to put instead of the two ?.



Could you shed some light on that?










share|cite|improve this question











$endgroup$




Suppose we have a system made up of two elements in parallel. I know that their lifetime, conditioned to $Theta = lambda$, are independent exponential with parameters respectively $lambda$ and $2lambda$. The density of $Theta$ is an exponential of parameter 1.



I want to calculate the probability that the system lasts for at least a time t.



Below is what I have done, I feel I am very close to the solution but I cannot work out where to integrate.



Let $T_1$ and $T_2$ be the lifetimes of the two devices.
By properties of conditional probability, I can write this:



$$max(T_1,T_2) = [max(T_1,T_2)vert lambda] *f(lambda)$$



Where $max(T_1,T_2)$ would be the joint density function.



Now I feel like I can write this:



$$mathbb{P}[max(T_1,T_2)>t] = int_?^?mathbb{P}[max(T_1,T_2)>tvert lambda] f(lambda)dlambda$$



However I am not sure what to put instead of the two ?.



Could you shed some light on that?







probability conditional-probability






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 7 at 9:15







qcc101

















asked Jan 7 at 8:49









qcc101qcc101

629213




629213












  • $begingroup$
    In general the integration limits is $-infty$ and $infty$. In your case since $Theta$ is exponential, the support is $(0, infty)$, so you can replace with that. (i.e. $f(lambda) = 0$ when $lambda leq 0$.)
    $endgroup$
    – BGM
    Jan 7 at 10:10


















  • $begingroup$
    In general the integration limits is $-infty$ and $infty$. In your case since $Theta$ is exponential, the support is $(0, infty)$, so you can replace with that. (i.e. $f(lambda) = 0$ when $lambda leq 0$.)
    $endgroup$
    – BGM
    Jan 7 at 10:10
















$begingroup$
In general the integration limits is $-infty$ and $infty$. In your case since $Theta$ is exponential, the support is $(0, infty)$, so you can replace with that. (i.e. $f(lambda) = 0$ when $lambda leq 0$.)
$endgroup$
– BGM
Jan 7 at 10:10




$begingroup$
In general the integration limits is $-infty$ and $infty$. In your case since $Theta$ is exponential, the support is $(0, infty)$, so you can replace with that. (i.e. $f(lambda) = 0$ when $lambda leq 0$.)
$endgroup$
– BGM
Jan 7 at 10:10










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%2f3064779%2fsystem-of-two-electronic-devices-in-parallel-with-conditional-lifetimes%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%2f3064779%2fsystem-of-two-electronic-devices-in-parallel-with-conditional-lifetimes%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

Bressuire

Cabo Verde

Gyllenstierna