I'm working on a example understanding Bayes, and wondering if my thought process is correct. So I have three users, and true or false if they own Nike or Reebok shoes, or both. I want to calculate the probability of Reebok's if they own Nike's. Here is my data:

User  | Nike  | Reebok 
Jesse | true  | false
Jake  | false | true 
John  | true  | true   - only user with both

Here is how I'm attempting to do this:

1) P(both/just Reebok) = 1/2 = 50%
2) P((total user with either - both)/total user with either = (3-1)/3 = 67% 3) Normalize P = 50%/(50%+67%) = 43%

So the result would be if a user owned Nike's, they have a 43% probability of owning Reebok's.

  • 4
    $\begingroup$ I don't see anything in this question that is Bayesian $\endgroup$ – Glen_b Aug 11 '15 at 3:27
  • 2
    $\begingroup$ There is no such a thing as "Naive Bayes Theorem" there is "Naive Bayes Algorithm" and "Bayes theorem". I edited your title. $\endgroup$ – Tim Aug 11 '15 at 12:20

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