Is there a big chance that Ithaca helps Dryden? Announcing the arrival of Valued Associate...

How fail-safe is nr as stop bytes?

How do I find out the mythology and history of my Fortress?

Is it possible for SQL statements to execute concurrently within a single session in SQL Server?

Can anything be seen from the center of the Boötes void? How dark would it be?

A term for a woman complaining about things/begging in a cute/childish way

Disembodied hand growing fangs

ArcGIS Pro Python arcpy.CreatePersonalGDB_management

Do wooden building fires get hotter than 600°C?

How does Python know the values already stored in its memory?

What would you call this weird metallic apparatus that allows you to lift people?

How do I use the new nonlinear finite element in Mathematica 12 for this equation?

Dating a Former Employee

Do I really need to have a message in a novel to appeal to readers?

When a candle burns, why does the top of wick glow if bottom of flame is hottest?

Converted a Scalar function to a TVF function for parallel execution-Still running in Serial mode

Question about debouncing - delay of state change

Take 2! Is this homebrew Lady of Pain warlock patron balanced?

Why should I vote and accept answers?

Is CEO the "profession" with the most psychopaths?

Did Deadpool rescue all of the X-Force?

Drawing without replacement: why is the order of draw irrelevant?

AppleTVs create a chatty alternate WiFi network

Amount of permutations on an NxNxN Rubik's Cube

How could we fake a moon landing now?



Is there a big chance that Ithaca helps Dryden?



Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern)Conditional probability problem and Alias Methodhelp with poissonPoisson process/probabilityPoisson(Exponential) Distribution questionPhone calls are received at Janice’s house according to a Poisson Process with parameter $lambda= 2$ per hour.Call Waiting Time process; questions on probabilities and expectations.The number of calls to receptionist per one hour has Poisson distribution with mean 1.Poisson Distribution question solvingtime between poisson eventswriting a poisson distribution












2












$begingroup$



Suppose calls to Dryden Fire Department arrive according to a Poisson Process with rate $0.5$ per hour. Suppose the time $T$ needed to respond to a call, return to the station and be ready for the next call is uniformly distributed between $0.5 $ hour and $1$ hour. If a new call comes before Dryden is ready to respond, then Ithaca fire station is requested to help. Suppose the Dryden fire station is ready to respond now. Then, find the probability distribution of the number of calls they will handle before they have to request Ithaca to help.




Okay, so i gathered that letting $N(t)$ be the number of calls by time $t$, $N(t)in Poisson(0.5t)$. Hence the interarrival time is $Exponential(0.5)$.



If $S$ is the interarrival time, then we "should be" interested in $P(S<T)$, which is the probability that the time between two consecutive calls is less than the time taken to respond to the previous call.



Now denoting the number of calls taken by Dryden before having to ask Ithaca for help, by $N$, we want to find $P(N=n)$ where $ngeq1$.



It seems that it has a Geometric distribution with $p=P(S<T)$ i.e. first success occurs when $S<T$.



However, I am getting $P(S<T)=(1-2e^{-1/4})^2$ which is not at all the answer. Answer is $P(N=n)=(1-p)^{n-1}p$ for $ngeq1$ where $p=e^{-1}-e^{-2}$. Also, is my reasoning right?










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    I agree with your answer (and reasoning). The supposedly correct answer seems to (a) suppose $Ssim Exp(2)$ instead of $Exp(1/2)$ and (b) swap $p$ and $1-p$. I can't see why they do either of those things.
    $endgroup$
    – Mick A
    Nov 13 '15 at 4:50
















2












$begingroup$



Suppose calls to Dryden Fire Department arrive according to a Poisson Process with rate $0.5$ per hour. Suppose the time $T$ needed to respond to a call, return to the station and be ready for the next call is uniformly distributed between $0.5 $ hour and $1$ hour. If a new call comes before Dryden is ready to respond, then Ithaca fire station is requested to help. Suppose the Dryden fire station is ready to respond now. Then, find the probability distribution of the number of calls they will handle before they have to request Ithaca to help.




Okay, so i gathered that letting $N(t)$ be the number of calls by time $t$, $N(t)in Poisson(0.5t)$. Hence the interarrival time is $Exponential(0.5)$.



If $S$ is the interarrival time, then we "should be" interested in $P(S<T)$, which is the probability that the time between two consecutive calls is less than the time taken to respond to the previous call.



Now denoting the number of calls taken by Dryden before having to ask Ithaca for help, by $N$, we want to find $P(N=n)$ where $ngeq1$.



It seems that it has a Geometric distribution with $p=P(S<T)$ i.e. first success occurs when $S<T$.



However, I am getting $P(S<T)=(1-2e^{-1/4})^2$ which is not at all the answer. Answer is $P(N=n)=(1-p)^{n-1}p$ for $ngeq1$ where $p=e^{-1}-e^{-2}$. Also, is my reasoning right?










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    I agree with your answer (and reasoning). The supposedly correct answer seems to (a) suppose $Ssim Exp(2)$ instead of $Exp(1/2)$ and (b) swap $p$ and $1-p$. I can't see why they do either of those things.
    $endgroup$
    – Mick A
    Nov 13 '15 at 4:50














2












2








2





$begingroup$



Suppose calls to Dryden Fire Department arrive according to a Poisson Process with rate $0.5$ per hour. Suppose the time $T$ needed to respond to a call, return to the station and be ready for the next call is uniformly distributed between $0.5 $ hour and $1$ hour. If a new call comes before Dryden is ready to respond, then Ithaca fire station is requested to help. Suppose the Dryden fire station is ready to respond now. Then, find the probability distribution of the number of calls they will handle before they have to request Ithaca to help.




Okay, so i gathered that letting $N(t)$ be the number of calls by time $t$, $N(t)in Poisson(0.5t)$. Hence the interarrival time is $Exponential(0.5)$.



If $S$ is the interarrival time, then we "should be" interested in $P(S<T)$, which is the probability that the time between two consecutive calls is less than the time taken to respond to the previous call.



Now denoting the number of calls taken by Dryden before having to ask Ithaca for help, by $N$, we want to find $P(N=n)$ where $ngeq1$.



It seems that it has a Geometric distribution with $p=P(S<T)$ i.e. first success occurs when $S<T$.



However, I am getting $P(S<T)=(1-2e^{-1/4})^2$ which is not at all the answer. Answer is $P(N=n)=(1-p)^{n-1}p$ for $ngeq1$ where $p=e^{-1}-e^{-2}$. Also, is my reasoning right?










share|cite|improve this question











$endgroup$





Suppose calls to Dryden Fire Department arrive according to a Poisson Process with rate $0.5$ per hour. Suppose the time $T$ needed to respond to a call, return to the station and be ready for the next call is uniformly distributed between $0.5 $ hour and $1$ hour. If a new call comes before Dryden is ready to respond, then Ithaca fire station is requested to help. Suppose the Dryden fire station is ready to respond now. Then, find the probability distribution of the number of calls they will handle before they have to request Ithaca to help.




Okay, so i gathered that letting $N(t)$ be the number of calls by time $t$, $N(t)in Poisson(0.5t)$. Hence the interarrival time is $Exponential(0.5)$.



If $S$ is the interarrival time, then we "should be" interested in $P(S<T)$, which is the probability that the time between two consecutive calls is less than the time taken to respond to the previous call.



Now denoting the number of calls taken by Dryden before having to ask Ithaca for help, by $N$, we want to find $P(N=n)$ where $ngeq1$.



It seems that it has a Geometric distribution with $p=P(S<T)$ i.e. first success occurs when $S<T$.



However, I am getting $P(S<T)=(1-2e^{-1/4})^2$ which is not at all the answer. Answer is $P(N=n)=(1-p)^{n-1}p$ for $ngeq1$ where $p=e^{-1}-e^{-2}$. Also, is my reasoning right?







probability probability-distributions random-variables poisson-distribution poisson-process






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 20 '15 at 22:20









BCLC

1




1










asked Nov 12 '15 at 15:15









Landon CarterLandon Carter

7,51811645




7,51811645








  • 1




    $begingroup$
    I agree with your answer (and reasoning). The supposedly correct answer seems to (a) suppose $Ssim Exp(2)$ instead of $Exp(1/2)$ and (b) swap $p$ and $1-p$. I can't see why they do either of those things.
    $endgroup$
    – Mick A
    Nov 13 '15 at 4:50














  • 1




    $begingroup$
    I agree with your answer (and reasoning). The supposedly correct answer seems to (a) suppose $Ssim Exp(2)$ instead of $Exp(1/2)$ and (b) swap $p$ and $1-p$. I can't see why they do either of those things.
    $endgroup$
    – Mick A
    Nov 13 '15 at 4:50








1




1




$begingroup$
I agree with your answer (and reasoning). The supposedly correct answer seems to (a) suppose $Ssim Exp(2)$ instead of $Exp(1/2)$ and (b) swap $p$ and $1-p$. I can't see why they do either of those things.
$endgroup$
– Mick A
Nov 13 '15 at 4:50




$begingroup$
I agree with your answer (and reasoning). The supposedly correct answer seems to (a) suppose $Ssim Exp(2)$ instead of $Exp(1/2)$ and (b) swap $p$ and $1-p$. I can't see why they do either of those things.
$endgroup$
– Mick A
Nov 13 '15 at 4:50










1 Answer
1






active

oldest

votes


















0












$begingroup$

Indeed, as @MickA pointed out, you made two mistakes here.



In this problem, you have the call at Dryden less than the prepared time for the first $(n-1)$ and greater than the prepared time for the $n$th call. Therefore, the success is defined as $S>T$, which is unusual.



Also, $Ssim exp(2)$ because $1/2$ is the rate of the poisson distribution of arrivals. Therefore, the mean of this poisson distribution is $2$. It follows the interarrival time should have an exponential distribution with rate $2$.






share|cite|improve this answer









$endgroup$














    Your Answer








    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%2f1525872%2fis-there-a-big-chance-that-ithaca-helps-dryden%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









    0












    $begingroup$

    Indeed, as @MickA pointed out, you made two mistakes here.



    In this problem, you have the call at Dryden less than the prepared time for the first $(n-1)$ and greater than the prepared time for the $n$th call. Therefore, the success is defined as $S>T$, which is unusual.



    Also, $Ssim exp(2)$ because $1/2$ is the rate of the poisson distribution of arrivals. Therefore, the mean of this poisson distribution is $2$. It follows the interarrival time should have an exponential distribution with rate $2$.






    share|cite|improve this answer









    $endgroup$


















      0












      $begingroup$

      Indeed, as @MickA pointed out, you made two mistakes here.



      In this problem, you have the call at Dryden less than the prepared time for the first $(n-1)$ and greater than the prepared time for the $n$th call. Therefore, the success is defined as $S>T$, which is unusual.



      Also, $Ssim exp(2)$ because $1/2$ is the rate of the poisson distribution of arrivals. Therefore, the mean of this poisson distribution is $2$. It follows the interarrival time should have an exponential distribution with rate $2$.






      share|cite|improve this answer









      $endgroup$
















        0












        0








        0





        $begingroup$

        Indeed, as @MickA pointed out, you made two mistakes here.



        In this problem, you have the call at Dryden less than the prepared time for the first $(n-1)$ and greater than the prepared time for the $n$th call. Therefore, the success is defined as $S>T$, which is unusual.



        Also, $Ssim exp(2)$ because $1/2$ is the rate of the poisson distribution of arrivals. Therefore, the mean of this poisson distribution is $2$. It follows the interarrival time should have an exponential distribution with rate $2$.






        share|cite|improve this answer









        $endgroup$



        Indeed, as @MickA pointed out, you made two mistakes here.



        In this problem, you have the call at Dryden less than the prepared time for the first $(n-1)$ and greater than the prepared time for the $n$th call. Therefore, the success is defined as $S>T$, which is unusual.



        Also, $Ssim exp(2)$ because $1/2$ is the rate of the poisson distribution of arrivals. Therefore, the mean of this poisson distribution is $2$. It follows the interarrival time should have an exponential distribution with rate $2$.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Oct 15 '18 at 22:07









        James WangJames Wang

        50728




        50728






























            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%2f1525872%2fis-there-a-big-chance-that-ithaca-helps-dryden%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

            Nidaros erkebispedøme

            Birsay

            Where did Arya get these scars? Unicorn Meta Zoo #1: Why another podcast? Announcing the arrival of Valued Associate #679: Cesar Manara Favourite questions and answers from the 1st quarter of 2019Why did Arya refuse to end it?Has the pronunciation of Arya Stark's name changed?Has Arya forgiven people?Why did Arya Stark lose her vision?Why can Arya still use the faces?Has the Narrow Sea become narrower?Does Arya Stark know how to make poisons outside of the House of Black and White?Why did Nymeria leave Arya?Why did Arya not kill the Lannister soldiers she encountered in the Riverlands?What is the current canonical age of Sansa, Bran and Arya Stark?