advertisement

THREE PROBABILITY RULES 1. The probability of any event is between 0 and 1.0 0 ≤ P(A) ≤ + 1.0 Probability of 0 = impossible Probability of 1.0 = certainty 2. The sum of the probabilities of all possible events to an experiment equals 1.0. P (tails) + P(heads) = 0.50 + 0.50 = 1.0 P (heart) + P(spade) + P(club) + P(diamond) = 0.25 + 0.25 +0.25 +0.25 = 1.0 3. The probability of an event is equal to the sum of the probabilities of all possible outcomes that comprise the event. P (heart) = P(2H + 3H + 4H ….AH) = 13/52 = 0.25