Conditional Probability Calculator

P(A|B): -

P(B|A): -

P(A∪B): -

Understanding Conditional Probability

What is Conditional Probability?

Conditional probability measures the likelihood of an event occurring given that another event has already occurred.

Key Formulas

  • P(A|B) = P(A∩B)/P(B)
  • P(B|A) = P(A∩B)/P(A)
  • P(A∪B) = P(A) + P(B) - P(A∩B)
  • Bayes' Theorem: P(A|B) = P(B|A)P(A)/P(B)

Probability Concepts

Basic Properties

0 ≤ P(A) ≤ 1

P(Sample Space) = 1

P(∅) = 0

Additivity for disjoint events

Independence

P(A|B) = P(A)

P(A∩B) = P(A)P(B)

Mutual independence

Pairwise independence

Chain Rule

P(A∩B∩C) = P(A)P(B|A)P(C|A∩B)

General multiplication rule

Sequential events

Tree diagrams

Total Probability

Law of total probability

Partition of sample space

Marginalization

Expected value calculation

Advanced Applications

Bayesian Statistics

Prior probability

Likelihood function

Posterior probability

Bayesian updating

Machine Learning

Naive Bayes classifier

Hidden Markov models

Probabilistic graphical models

Maximum likelihood estimation

Decision Theory

Expected utility

Risk assessment

Decision trees

Optimal decisions

Real-world Applications

Medical diagnosis

Weather forecasting

Quality control

Financial risk analysis