Conditional probability refers to the chances that some outcome (A) occurs given that another event (B) has already occurred. In probability, this is written as A given B, or as this formula: P(A ...

Conditional probability looks at the likelihood of an event occurring based on the prior occurrence of another event (e.g., if I walk on the ice, what is the probability I will fall).

Visualizing conditional probability: Visualizing Conditional Probability By dragging the sliders, users can change the probabilities of events A and B. The applet shows the two probabilities as areas.

In analyzing the general election race, it’s only the conditional probabilities that matter. If Bush is good enough to win the primary, he’s probably good enough to give Republicans about a 50 ...