Probability Formulas

0 ≤ p(A) ≤ 1

p(S) = 1

Probability Formulas

Probability Formulas


Probability Formula

Probability Formula


Addition Rule

If A intersección B ≠ Conjunto vacio.

p(A unión B) = p(A) + p(B) − p(A intersección B)

p(A unión B unión C) = p(A) + p(B) + p(C) − p(A intersección B) − p(A intersección C) − p(B intersección C) + p(A intersección B intersección C)


Multiplication Rule

Independent Events

p(A intersección B) = p(A) · p(B)

Dependent Events

p(A intersección B) = p(A) · p(B|A)


Conditional Probability

Conditional Probability Formula

Independent Events

p(A|B) = p(A)

Dependent Events

p(A|B) ≠ p(A)


Law of Total Probability

p(B) = p(A1) · p(B|A1) + p(A2) · p(B|A2 ) + ... + p(An) · p(B|An )


Bayes' Theorem

Bayes' Theorem Formula


Expected Value

Expected Value Formula


Variance of a Discrete Random Variable

Variance of a Discrete Random Variable

Standard Deviation of a Discrete Random Variable

Standard Deviation of a Discrete Random Variable


Binomial Distribution

Binomial Distribution Formula

Binomial Coefficient


Normal Approximation to the Binomial

Normal Approximation to the Binomial

Normal Approximation to the Binomial