Encyclopedia > Conditional probability

  Article Content

Conditional probability

In probability theory, conditional probability is the probability that some event A occurs, knowing that event B occurs. It is written P(A|B), read "the probability of A, given B".

If A and B are events, and P(B) > 0, then

P(A|B) = P(AB) / P(B).
If A and B are independent events (that is, the occurrence of either one does not affect the occurrence of the other in any way), then P(A ∩ B) = P(A) · P(B), so P(A|B) = P(A).

If B is an event and P(B) > 0, then the function Q defined by Q(A) = P(A|B) for all events A is a probability measure.



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Dana International

... - Wikipedia <<Up     Contents Dana International Dana International (born Yaron Cohen February 2, 1972) is an Israeli transsexual pop ...

 
 
 
This page was created in 36.3 ms