# Probability

Basic reference for probability that I find myself looking up.

Probability of $$X$$:

$P(X)$

When $$X$$ and $$Y$$ are independent:

$P(X \cap Y) = P(X) P(Y)$

Conditional probability of $$X$$ given $$C$$:

$P(X \mid C) = \frac{P(X \cap C)}{P(C)}$

Bayes’ theorem:

$P(X \mid Y) = \frac{P(Y \mid X) P(X)}{P(Y)}$