how to prove Bayes theorem?












0












$begingroup$


how to prove Bayes theorem? (Develop from conditional probability )
2 criterias
-Total of law is probability
-multiplication rule
Can someone show me the mathematical proof & steps for this please?










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  • 1




    $begingroup$
    There's a perfectly good proof on Wikipedia. Are there steps there that you don't follow and would like more explanation on?
    $endgroup$
    – Nick Peterson
    Dec 5 '18 at 16:16






  • 1




    $begingroup$
    There isn't much to prove at all...
    $endgroup$
    – Federico
    Dec 5 '18 at 16:17
















0












$begingroup$


how to prove Bayes theorem? (Develop from conditional probability )
2 criterias
-Total of law is probability
-multiplication rule
Can someone show me the mathematical proof & steps for this please?










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    There's a perfectly good proof on Wikipedia. Are there steps there that you don't follow and would like more explanation on?
    $endgroup$
    – Nick Peterson
    Dec 5 '18 at 16:16






  • 1




    $begingroup$
    There isn't much to prove at all...
    $endgroup$
    – Federico
    Dec 5 '18 at 16:17














0












0








0





$begingroup$


how to prove Bayes theorem? (Develop from conditional probability )
2 criterias
-Total of law is probability
-multiplication rule
Can someone show me the mathematical proof & steps for this please?










share|cite|improve this question









$endgroup$




how to prove Bayes theorem? (Develop from conditional probability )
2 criterias
-Total of law is probability
-multiplication rule
Can someone show me the mathematical proof & steps for this please?







conditional-probability






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share|cite|improve this question




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asked Dec 5 '18 at 16:12









Amber Amber

11




11








  • 1




    $begingroup$
    There's a perfectly good proof on Wikipedia. Are there steps there that you don't follow and would like more explanation on?
    $endgroup$
    – Nick Peterson
    Dec 5 '18 at 16:16






  • 1




    $begingroup$
    There isn't much to prove at all...
    $endgroup$
    – Federico
    Dec 5 '18 at 16:17














  • 1




    $begingroup$
    There's a perfectly good proof on Wikipedia. Are there steps there that you don't follow and would like more explanation on?
    $endgroup$
    – Nick Peterson
    Dec 5 '18 at 16:16






  • 1




    $begingroup$
    There isn't much to prove at all...
    $endgroup$
    – Federico
    Dec 5 '18 at 16:17








1




1




$begingroup$
There's a perfectly good proof on Wikipedia. Are there steps there that you don't follow and would like more explanation on?
$endgroup$
– Nick Peterson
Dec 5 '18 at 16:16




$begingroup$
There's a perfectly good proof on Wikipedia. Are there steps there that you don't follow and would like more explanation on?
$endgroup$
– Nick Peterson
Dec 5 '18 at 16:16




1




1




$begingroup$
There isn't much to prove at all...
$endgroup$
– Federico
Dec 5 '18 at 16:17




$begingroup$
There isn't much to prove at all...
$endgroup$
– Federico
Dec 5 '18 at 16:17










2 Answers
2






active

oldest

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3












$begingroup$

The conditional probability is defined as
$$
P(A|B) = frac{P(Acap B)}{P(B)},
$$

hence
$$
P(A|B) P(B) = P(B|A) P(A) .
$$






share|cite|improve this answer









$endgroup$





















    1












    $begingroup$

    Hints




    • Write $P(A cap B)$ two different ways using conditional probability

    • these are therefore equal by Euclid's first axiom

    • manipulate into Bayes' theorem (assuming none of the probabilities are $0$)






    share|cite|improve this answer









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      2 Answers
      2






      active

      oldest

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      2 Answers
      2






      active

      oldest

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      active

      oldest

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      active

      oldest

      votes









      3












      $begingroup$

      The conditional probability is defined as
      $$
      P(A|B) = frac{P(Acap B)}{P(B)},
      $$

      hence
      $$
      P(A|B) P(B) = P(B|A) P(A) .
      $$






      share|cite|improve this answer









      $endgroup$


















        3












        $begingroup$

        The conditional probability is defined as
        $$
        P(A|B) = frac{P(Acap B)}{P(B)},
        $$

        hence
        $$
        P(A|B) P(B) = P(B|A) P(A) .
        $$






        share|cite|improve this answer









        $endgroup$
















          3












          3








          3





          $begingroup$

          The conditional probability is defined as
          $$
          P(A|B) = frac{P(Acap B)}{P(B)},
          $$

          hence
          $$
          P(A|B) P(B) = P(B|A) P(A) .
          $$






          share|cite|improve this answer









          $endgroup$



          The conditional probability is defined as
          $$
          P(A|B) = frac{P(Acap B)}{P(B)},
          $$

          hence
          $$
          P(A|B) P(B) = P(B|A) P(A) .
          $$







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Dec 5 '18 at 16:19









          FedericoFederico

          5,014514




          5,014514























              1












              $begingroup$

              Hints




              • Write $P(A cap B)$ two different ways using conditional probability

              • these are therefore equal by Euclid's first axiom

              • manipulate into Bayes' theorem (assuming none of the probabilities are $0$)






              share|cite|improve this answer









              $endgroup$


















                1












                $begingroup$

                Hints




                • Write $P(A cap B)$ two different ways using conditional probability

                • these are therefore equal by Euclid's first axiom

                • manipulate into Bayes' theorem (assuming none of the probabilities are $0$)






                share|cite|improve this answer









                $endgroup$
















                  1












                  1








                  1





                  $begingroup$

                  Hints




                  • Write $P(A cap B)$ two different ways using conditional probability

                  • these are therefore equal by Euclid's first axiom

                  • manipulate into Bayes' theorem (assuming none of the probabilities are $0$)






                  share|cite|improve this answer









                  $endgroup$



                  Hints




                  • Write $P(A cap B)$ two different ways using conditional probability

                  • these are therefore equal by Euclid's first axiom

                  • manipulate into Bayes' theorem (assuming none of the probabilities are $0$)







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered Dec 5 '18 at 16:18









                  HenryHenry

                  99.7k479165




                  99.7k479165






























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