Biased dice probability question Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Probability of dice thrownDice and probabilityDetermine whether the dice is biased based on 10 rollsProbability of events with biased diceProbability of biased diceProbability on biased diceProbability of rolling 2 and 3 numbers in a sequence when rolling 3, 6 sided diceDice probability helpProbability of an “at least” QuestionProbability of biased die.

Writing Thesis: Copying from published papers

What computer would be fastest for Mathematica Home Edition?

Slither Like a Snake

Did the new image of black hole confirm the general theory of relativity?

Should you tell Jews they are breaking a commandment?

When is phishing education going too far?

Does a C shift expression have unsigned type? Why would Splint warn about a right-shift?

Why don't the Weasley twins use magic outside of school if the Trace can only find the location of spells cast?

Stop battery usage [Ubuntu 18]

How should I respond to a player wanting to catch a sword between their hands?

Windows 10: How to Lock (not sleep) laptop on lid close?

How to colour the US map with Yellow, Green, Red and Blue to minimize the number of states with the colour of Green

Complexity of many constant time steps with occasional logarithmic steps

What is the largest species of polychaete?

Do we know why communications with Beresheet and NASA were lost during the attempted landing of the Moon lander?

Keep going mode for require-package

How does modal jazz use chord progressions?

If I can make up priors, why can't I make up posteriors?

Active filter with series inductor and resistor - do these exist?

What's the point in a preamp?

3 doors, three guards, one stone

Can a monk deflect thrown melee weapons?

Unable to start mainnet node docker container

Can a zero nonce be safely used with AES-GCM if the key is random and never used again?



Biased dice probability question



Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Probability of dice thrownDice and probabilityDetermine whether the dice is biased based on 10 rollsProbability of events with biased diceProbability of biased diceProbability on biased diceProbability of rolling 2 and 3 numbers in a sequence when rolling 3, 6 sided diceDice probability helpProbability of an “at least” QuestionProbability of biased die.










4












$begingroup$


A biased six sided dice is rolled twice. Show that the probability that the two results are the same is at least $frac16$.
(Hint: $(p_1 − a)^2 + . . . + (p_6 − a)^2 ≥ 0$ and choose suitable
$p_1, . . . , p_6$, a.)










share|cite|improve this question









New contributor




mandy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$











  • $begingroup$
    Hint: First try to show that if a coin is flipped twice, the probability that the two results are the same is at least $1/2$. This will help you figure out what to choose as $a$.
    $endgroup$
    – Lorenzo
    33 mins ago















4












$begingroup$


A biased six sided dice is rolled twice. Show that the probability that the two results are the same is at least $frac16$.
(Hint: $(p_1 − a)^2 + . . . + (p_6 − a)^2 ≥ 0$ and choose suitable
$p_1, . . . , p_6$, a.)










share|cite|improve this question









New contributor




mandy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$











  • $begingroup$
    Hint: First try to show that if a coin is flipped twice, the probability that the two results are the same is at least $1/2$. This will help you figure out what to choose as $a$.
    $endgroup$
    – Lorenzo
    33 mins ago













4












4








4


2



$begingroup$


A biased six sided dice is rolled twice. Show that the probability that the two results are the same is at least $frac16$.
(Hint: $(p_1 − a)^2 + . . . + (p_6 − a)^2 ≥ 0$ and choose suitable
$p_1, . . . , p_6$, a.)










share|cite|improve this question









New contributor




mandy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




A biased six sided dice is rolled twice. Show that the probability that the two results are the same is at least $frac16$.
(Hint: $(p_1 − a)^2 + . . . + (p_6 − a)^2 ≥ 0$ and choose suitable
$p_1, . . . , p_6$, a.)







probability






share|cite|improve this question









New contributor




mandy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|cite|improve this question









New contributor




mandy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|cite|improve this question




share|cite|improve this question








edited 43 mins ago









mathpadawan

2,019422




2,019422






New contributor




mandy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 46 mins ago









mandymandy

211




211




New contributor




mandy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





mandy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






mandy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











  • $begingroup$
    Hint: First try to show that if a coin is flipped twice, the probability that the two results are the same is at least $1/2$. This will help you figure out what to choose as $a$.
    $endgroup$
    – Lorenzo
    33 mins ago
















  • $begingroup$
    Hint: First try to show that if a coin is flipped twice, the probability that the two results are the same is at least $1/2$. This will help you figure out what to choose as $a$.
    $endgroup$
    – Lorenzo
    33 mins ago















$begingroup$
Hint: First try to show that if a coin is flipped twice, the probability that the two results are the same is at least $1/2$. This will help you figure out what to choose as $a$.
$endgroup$
– Lorenzo
33 mins ago




$begingroup$
Hint: First try to show that if a coin is flipped twice, the probability that the two results are the same is at least $1/2$. This will help you figure out what to choose as $a$.
$endgroup$
– Lorenzo
33 mins ago










1 Answer
1






active

oldest

votes


















4












$begingroup$

Let $p_i$ be the probability of rolling $i$. Then $sum_i=1^6 p_i = 1$.



By Cauchy-Schwarz inequality,



$$beginalign*
left(sum_i=1^6 1^2right) left(sum_i=1^6 p_i^2right) &ge
left(sum_i=1^6 1p_iright)^2\
6left(sum_i=1^6 p_i^2right) &ge 1\
sum_i=1^6 p_i^2 &ge frac16endalign*$$



Equality holds when all the $p_i$ are the same, i.e. when the die is unbiased.






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
    );



    );






    mandy is a new contributor. Be nice, and check out our Code of Conduct.









    draft saved

    draft discarded


















    StackExchange.ready(
    function ()
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3188165%2fbiased-dice-probability-question%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









    4












    $begingroup$

    Let $p_i$ be the probability of rolling $i$. Then $sum_i=1^6 p_i = 1$.



    By Cauchy-Schwarz inequality,



    $$beginalign*
    left(sum_i=1^6 1^2right) left(sum_i=1^6 p_i^2right) &ge
    left(sum_i=1^6 1p_iright)^2\
    6left(sum_i=1^6 p_i^2right) &ge 1\
    sum_i=1^6 p_i^2 &ge frac16endalign*$$



    Equality holds when all the $p_i$ are the same, i.e. when the die is unbiased.






    share|cite|improve this answer









    $endgroup$

















      4












      $begingroup$

      Let $p_i$ be the probability of rolling $i$. Then $sum_i=1^6 p_i = 1$.



      By Cauchy-Schwarz inequality,



      $$beginalign*
      left(sum_i=1^6 1^2right) left(sum_i=1^6 p_i^2right) &ge
      left(sum_i=1^6 1p_iright)^2\
      6left(sum_i=1^6 p_i^2right) &ge 1\
      sum_i=1^6 p_i^2 &ge frac16endalign*$$



      Equality holds when all the $p_i$ are the same, i.e. when the die is unbiased.






      share|cite|improve this answer









      $endgroup$















        4












        4








        4





        $begingroup$

        Let $p_i$ be the probability of rolling $i$. Then $sum_i=1^6 p_i = 1$.



        By Cauchy-Schwarz inequality,



        $$beginalign*
        left(sum_i=1^6 1^2right) left(sum_i=1^6 p_i^2right) &ge
        left(sum_i=1^6 1p_iright)^2\
        6left(sum_i=1^6 p_i^2right) &ge 1\
        sum_i=1^6 p_i^2 &ge frac16endalign*$$



        Equality holds when all the $p_i$ are the same, i.e. when the die is unbiased.






        share|cite|improve this answer









        $endgroup$



        Let $p_i$ be the probability of rolling $i$. Then $sum_i=1^6 p_i = 1$.



        By Cauchy-Schwarz inequality,



        $$beginalign*
        left(sum_i=1^6 1^2right) left(sum_i=1^6 p_i^2right) &ge
        left(sum_i=1^6 1p_iright)^2\
        6left(sum_i=1^6 p_i^2right) &ge 1\
        sum_i=1^6 p_i^2 &ge frac16endalign*$$



        Equality holds when all the $p_i$ are the same, i.e. when the die is unbiased.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered 32 mins ago









        peterwhypeterwhy

        12.3k21229




        12.3k21229




















            mandy is a new contributor. Be nice, and check out our Code of Conduct.









            draft saved

            draft discarded


















            mandy is a new contributor. Be nice, and check out our Code of Conduct.












            mandy is a new contributor. Be nice, and check out our Code of Conduct.











            mandy is a new contributor. Be nice, and check out our Code of Conduct.














            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%2f3188165%2fbiased-dice-probability-question%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

            Invision Community Contents History See also References External links Navigation menuProprietaryinvisioncommunity.comIPS Community ForumsIPS Community Forumsthis blog entry"License Changes, IP.Board 3.4, and the Future""Interview -- Matt Mecham of Ibforums""CEO Invision Power Board, Matt Mecham Is a Liar, Thief!"IPB License Explanation 1.3, 1.3.1, 2.0, and 2.1ArchivedSecurity Fixes, Updates And Enhancements For IPB 1.3.1Archived"New Demo Accounts - Invision Power Services"the original"New Default Skin"the original"Invision Power Board 3.0.0 and Applications Released"the original"Archived copy"the original"Perpetual licenses being done away with""Release Notes - Invision Power Services""Introducing: IPS Community Suite 4!"Invision Community Release Notes

            Canceling a color specificationRandomly assigning color to Graphics3D objects?Default color for Filling in Mathematica 9Coloring specific elements of sets with a prime modified order in an array plotHow to pick a color differing significantly from the colors already in a given color list?Detection of the text colorColor numbers based on their valueCan color schemes for use with ColorData include opacity specification?My dynamic color schemes

            Ласкавець круглолистий Зміст Опис | Поширення | Галерея | Примітки | Посилання | Навігаційне меню58171138361-22960890446Bupleurum rotundifoliumEuro+Med PlantbasePlants of the World Online — Kew ScienceGermplasm Resources Information Network (GRIN)Ласкавецькн. VI : Літери Ком — Левиправивши або дописавши її