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2.1.1.4 Conditional Probabilities

Definition 4   If A and B are events in $ \Omega$, the conditional probability of A given B is:

$\displaystyle P(A\vert B) = \frac{P(A \cap B)}{P(B)}$

Note that:

  1. $ P(A \cap B) = P(A\vert B) P(B)$
  2. $ P(A^c \vert B) + P(A \vert B) = 1$



Eran Borenstein
2007-05-04