Intersection and conditioned set












0














I don't understand why if it's true that $P(Acap B|C)=P(A|C)cdot P(B|C)$ (formula, moreover, used in a number of exercises), in this case he writes:
enter image description here










share|cite|improve this question


















  • 1




    Actually, I do not believe that $P(Acap B|C)=P(A|C)cdot P(B|C)$ was used in the calculation. It seems more to be something like $P(Acap B|C)=P(A|B)cdot P(B|C)$. This is not true in general, there has to be some assumption on $A,B,C$. What is true however is that $P(Acap B|C)=P(A|B cap C)cdot P(B|C)$.
    – Matthias Klupsch
    Nov 21 '18 at 10:28










  • @MatthiasKlupsch Thanks for your answer. Well, you're welcome to watch the solution that i post below.
    – Marco Pittella
    Nov 21 '18 at 10:33










  • @MatthiasKlupsch I'm sorry for my reponse comment, i don't speak english so well. In any case, the photo up here is referring to the following exercise. You have 5 coins and $p_i$ is the probability that the $i$ coin gives Head (T), where $p_1=0,p_2=0,25,p_3=0,5,p_4=0,75,p_5=1$. One coin is extrracted and launched. You obtain Head (T). If the same $i$ coin launched again, what is the probability to obtain another Head (T)?
    – Marco Pittella
    Nov 21 '18 at 10:48


















0














I don't understand why if it's true that $P(Acap B|C)=P(A|C)cdot P(B|C)$ (formula, moreover, used in a number of exercises), in this case he writes:
enter image description here










share|cite|improve this question


















  • 1




    Actually, I do not believe that $P(Acap B|C)=P(A|C)cdot P(B|C)$ was used in the calculation. It seems more to be something like $P(Acap B|C)=P(A|B)cdot P(B|C)$. This is not true in general, there has to be some assumption on $A,B,C$. What is true however is that $P(Acap B|C)=P(A|B cap C)cdot P(B|C)$.
    – Matthias Klupsch
    Nov 21 '18 at 10:28










  • @MatthiasKlupsch Thanks for your answer. Well, you're welcome to watch the solution that i post below.
    – Marco Pittella
    Nov 21 '18 at 10:33










  • @MatthiasKlupsch I'm sorry for my reponse comment, i don't speak english so well. In any case, the photo up here is referring to the following exercise. You have 5 coins and $p_i$ is the probability that the $i$ coin gives Head (T), where $p_1=0,p_2=0,25,p_3=0,5,p_4=0,75,p_5=1$. One coin is extrracted and launched. You obtain Head (T). If the same $i$ coin launched again, what is the probability to obtain another Head (T)?
    – Marco Pittella
    Nov 21 '18 at 10:48
















0












0








0


1





I don't understand why if it's true that $P(Acap B|C)=P(A|C)cdot P(B|C)$ (formula, moreover, used in a number of exercises), in this case he writes:
enter image description here










share|cite|improve this question













I don't understand why if it's true that $P(Acap B|C)=P(A|C)cdot P(B|C)$ (formula, moreover, used in a number of exercises), in this case he writes:
enter image description here







probability statistics elementary-set-theory boolean-algebra






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Nov 21 '18 at 10:19









Marco Pittella

1258




1258








  • 1




    Actually, I do not believe that $P(Acap B|C)=P(A|C)cdot P(B|C)$ was used in the calculation. It seems more to be something like $P(Acap B|C)=P(A|B)cdot P(B|C)$. This is not true in general, there has to be some assumption on $A,B,C$. What is true however is that $P(Acap B|C)=P(A|B cap C)cdot P(B|C)$.
    – Matthias Klupsch
    Nov 21 '18 at 10:28










  • @MatthiasKlupsch Thanks for your answer. Well, you're welcome to watch the solution that i post below.
    – Marco Pittella
    Nov 21 '18 at 10:33










  • @MatthiasKlupsch I'm sorry for my reponse comment, i don't speak english so well. In any case, the photo up here is referring to the following exercise. You have 5 coins and $p_i$ is the probability that the $i$ coin gives Head (T), where $p_1=0,p_2=0,25,p_3=0,5,p_4=0,75,p_5=1$. One coin is extrracted and launched. You obtain Head (T). If the same $i$ coin launched again, what is the probability to obtain another Head (T)?
    – Marco Pittella
    Nov 21 '18 at 10:48
















  • 1




    Actually, I do not believe that $P(Acap B|C)=P(A|C)cdot P(B|C)$ was used in the calculation. It seems more to be something like $P(Acap B|C)=P(A|B)cdot P(B|C)$. This is not true in general, there has to be some assumption on $A,B,C$. What is true however is that $P(Acap B|C)=P(A|B cap C)cdot P(B|C)$.
    – Matthias Klupsch
    Nov 21 '18 at 10:28










  • @MatthiasKlupsch Thanks for your answer. Well, you're welcome to watch the solution that i post below.
    – Marco Pittella
    Nov 21 '18 at 10:33










  • @MatthiasKlupsch I'm sorry for my reponse comment, i don't speak english so well. In any case, the photo up here is referring to the following exercise. You have 5 coins and $p_i$ is the probability that the $i$ coin gives Head (T), where $p_1=0,p_2=0,25,p_3=0,5,p_4=0,75,p_5=1$. One coin is extrracted and launched. You obtain Head (T). If the same $i$ coin launched again, what is the probability to obtain another Head (T)?
    – Marco Pittella
    Nov 21 '18 at 10:48










1




1




Actually, I do not believe that $P(Acap B|C)=P(A|C)cdot P(B|C)$ was used in the calculation. It seems more to be something like $P(Acap B|C)=P(A|B)cdot P(B|C)$. This is not true in general, there has to be some assumption on $A,B,C$. What is true however is that $P(Acap B|C)=P(A|B cap C)cdot P(B|C)$.
– Matthias Klupsch
Nov 21 '18 at 10:28




Actually, I do not believe that $P(Acap B|C)=P(A|C)cdot P(B|C)$ was used in the calculation. It seems more to be something like $P(Acap B|C)=P(A|B)cdot P(B|C)$. This is not true in general, there has to be some assumption on $A,B,C$. What is true however is that $P(Acap B|C)=P(A|B cap C)cdot P(B|C)$.
– Matthias Klupsch
Nov 21 '18 at 10:28












@MatthiasKlupsch Thanks for your answer. Well, you're welcome to watch the solution that i post below.
– Marco Pittella
Nov 21 '18 at 10:33




@MatthiasKlupsch Thanks for your answer. Well, you're welcome to watch the solution that i post below.
– Marco Pittella
Nov 21 '18 at 10:33












@MatthiasKlupsch I'm sorry for my reponse comment, i don't speak english so well. In any case, the photo up here is referring to the following exercise. You have 5 coins and $p_i$ is the probability that the $i$ coin gives Head (T), where $p_1=0,p_2=0,25,p_3=0,5,p_4=0,75,p_5=1$. One coin is extrracted and launched. You obtain Head (T). If the same $i$ coin launched again, what is the probability to obtain another Head (T)?
– Marco Pittella
Nov 21 '18 at 10:48






@MatthiasKlupsch I'm sorry for my reponse comment, i don't speak english so well. In any case, the photo up here is referring to the following exercise. You have 5 coins and $p_i$ is the probability that the $i$ coin gives Head (T), where $p_1=0,p_2=0,25,p_3=0,5,p_4=0,75,p_5=1$. One coin is extrracted and launched. You obtain Head (T). If the same $i$ coin launched again, what is the probability to obtain another Head (T)?
– Marco Pittella
Nov 21 '18 at 10:48












1 Answer
1






active

oldest

votes


















0














Example like the following: this



Thanks again.






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%2f3007529%2fintersection-and-conditioned-set%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














    Example like the following: this



    Thanks again.






    share|cite|improve this answer


























      0














      Example like the following: this



      Thanks again.






      share|cite|improve this answer
























        0












        0








        0






        Example like the following: this



        Thanks again.






        share|cite|improve this answer












        Example like the following: this



        Thanks again.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Nov 21 '18 at 10:34









        Marco Pittella

        1258




        1258






























            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%2f3007529%2fintersection-and-conditioned-set%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

            Can a sorcerer learn a 5th-level spell early by creating spell slots using the Font of Magic feature?

            Does disintegrating a polymorphed enemy still kill it after the 2018 errata?

            A Topological Invariant for $pi_3(U(n))$