Probability

• What is the conditional probability formula?

  P(AnB) = P(A) P(B | A)
• What is the formula for permutations?

  n! / (n - r)!
• What is the formula for combinations?

  n! / (r!(n - r)!)
• What is the formula for independent events?

  P(A | B) = P(A)
• What is the product rule for independent events?

  P(A ∩ B) = P(A) * P(B)
• What is Bayes' Theorem used for?

  Calculating conditional probabilities
• What is the general notation for Bayes' Theorem?

  P(A | B) = P(B | A)P(A) / P(B)
• How is P(B) calculated in Bayes' Theorem?

  P(B) = Σ P(B | A_i)P(A_i)
• Calculating P(B|A)


  P(B|A)=P(AnB)/ P(A)
• P(AnB) when mutually exclusive

  P(AnB)=P(A) + P(B)
• Diagram of P with A/B


  Remember this

  
• How to calculate P(A'nB')

  1-P(AuB)
• Calculate the probability that exactly one occurs

  Do 1-P(AnB)-outside bit

  e.g