conditional probability

American  

noun

1. Statistics, Mathematics. the probability that an event will occur under the condition that another event occurs first: equal to the probability that both will occur divided by the probability that the first will occur.

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conditional probability British  

noun

1. statistics the probability of one event, A, occurring given that another, B, is already known to have occurred: written P ( A|B ) and equal to P ( A and B )| P ( B )

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Etymology

Origin of conditional probability

First recorded in 1960–65

Example Sentences

Bayes’ theorem is a statement about conditional probability—the probability of an event given other known conditions.

From Scientific American

This conclusion is based on a faulty understanding of life expectancy, which is a conditional probability of surviving to a given age.

From Washington Post

We model each conditional probability distribution as follows:

From Nature

In any case, given that a family has at least one daughter, what is the conditional probability that it also has a son?

From Literature

The attraction of Bayes's theorem, as Silver presents it, is that it concerns conditional probability: the probability that a theory or hypothesis is true if some event has happened.

From The Guardian