General Probability Rules

  • discovered by Russian mathematician Kolmogorov, also known as “Probability Calculus”
  • probability = function of any set of outcomes and assigns it a number between 0 and 1
    • \(0 \le P(E) \le 1\), where \(E\) = event
  • probability that nothing occurs = 0 (impossible, have to roll dice to create outcome), that something occurs is 1 (certain)
  • probability of outcome or event \(E\), \(P(E)\) = ratio of ways that \(E\) could occur to number of all possible outcomes or events
  • probability of something = 1 - probability of the opposite occurring
  • probability of the union of any two sets of outcomes that have nothing in common (mutually exclusive) = sum of respective probabilities