difference of two independent exponentially distributed random variables












0














Let $X_1,X_2,X_3$ be independent $Exp(lambda)$ distributed random variables. I need to find $P(X_1<X_2<X_3)$.



I think we need to use independence, then we can rewrite $P(X_1<X_2<X_3)=P(X_1<X_2)P(X_2<X_3)$, but I don't know how to proceed next. Maybe considering $Y=X_1-X_2$, but then we need to find the distribution of Y, which is hard for me.



Any help would be appreciated, thanks.










share|cite|improve this question



























    0














    Let $X_1,X_2,X_3$ be independent $Exp(lambda)$ distributed random variables. I need to find $P(X_1<X_2<X_3)$.



    I think we need to use independence, then we can rewrite $P(X_1<X_2<X_3)=P(X_1<X_2)P(X_2<X_3)$, but I don't know how to proceed next. Maybe considering $Y=X_1-X_2$, but then we need to find the distribution of Y, which is hard for me.



    Any help would be appreciated, thanks.










    share|cite|improve this question

























      0












      0








      0







      Let $X_1,X_2,X_3$ be independent $Exp(lambda)$ distributed random variables. I need to find $P(X_1<X_2<X_3)$.



      I think we need to use independence, then we can rewrite $P(X_1<X_2<X_3)=P(X_1<X_2)P(X_2<X_3)$, but I don't know how to proceed next. Maybe considering $Y=X_1-X_2$, but then we need to find the distribution of Y, which is hard for me.



      Any help would be appreciated, thanks.










      share|cite|improve this question













      Let $X_1,X_2,X_3$ be independent $Exp(lambda)$ distributed random variables. I need to find $P(X_1<X_2<X_3)$.



      I think we need to use independence, then we can rewrite $P(X_1<X_2<X_3)=P(X_1<X_2)P(X_2<X_3)$, but I don't know how to proceed next. Maybe considering $Y=X_1-X_2$, but then we need to find the distribution of Y, which is hard for me.



      Any help would be appreciated, thanks.







      probability






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 22 '18 at 17:15









      dxdydzdxdydz

      1949




      1949






















          1 Answer
          1






          active

          oldest

          votes


















          2














          By symmetry,



          we have



          begin{align}P(X_1<X_2<X_3)&=P(X_1<X_3<X_2)\&=P(X_2<X_1<X_3)\ &=P(X_2<X_3<X_1)\ &=P(X_3<X_1<X_2)\ &=P(X_3<X_2<X_1)\ end{align}



          Since they have to sum up to $1$, $$P(X_1<X_2<X_3)=frac16$$






          share|cite|improve this answer





















            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%2f3009372%2fdifference-of-two-independent-exponentially-distributed-random-variables%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            2














            By symmetry,



            we have



            begin{align}P(X_1<X_2<X_3)&=P(X_1<X_3<X_2)\&=P(X_2<X_1<X_3)\ &=P(X_2<X_3<X_1)\ &=P(X_3<X_1<X_2)\ &=P(X_3<X_2<X_1)\ end{align}



            Since they have to sum up to $1$, $$P(X_1<X_2<X_3)=frac16$$






            share|cite|improve this answer


























              2














              By symmetry,



              we have



              begin{align}P(X_1<X_2<X_3)&=P(X_1<X_3<X_2)\&=P(X_2<X_1<X_3)\ &=P(X_2<X_3<X_1)\ &=P(X_3<X_1<X_2)\ &=P(X_3<X_2<X_1)\ end{align}



              Since they have to sum up to $1$, $$P(X_1<X_2<X_3)=frac16$$






              share|cite|improve this answer
























                2












                2








                2






                By symmetry,



                we have



                begin{align}P(X_1<X_2<X_3)&=P(X_1<X_3<X_2)\&=P(X_2<X_1<X_3)\ &=P(X_2<X_3<X_1)\ &=P(X_3<X_1<X_2)\ &=P(X_3<X_2<X_1)\ end{align}



                Since they have to sum up to $1$, $$P(X_1<X_2<X_3)=frac16$$






                share|cite|improve this answer












                By symmetry,



                we have



                begin{align}P(X_1<X_2<X_3)&=P(X_1<X_3<X_2)\&=P(X_2<X_1<X_3)\ &=P(X_2<X_3<X_1)\ &=P(X_3<X_1<X_2)\ &=P(X_3<X_2<X_1)\ end{align}



                Since they have to sum up to $1$, $$P(X_1<X_2<X_3)=frac16$$







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Nov 22 '18 at 17:32









                Siong Thye GohSiong Thye Goh

                99.6k1464117




                99.6k1464117






























                    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%2f3009372%2fdifference-of-two-independent-exponentially-distributed-random-variables%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

                    mysqli_query(): Empty query in /home/lucindabrummitt/public_html/blog/wp-includes/wp-db.php on line 1924

                    How to change which sound is reproduced for terminal bell?

                    Can I use Tabulator js library in my java Spring + Thymeleaf project?