Chapter 5 Vocabulary Review
Addition Rule for Disjoint Events – P(A or B) = P(A) + P(B)
Complement Rule – Used to find the probability that an event does not occur. Also used to find
the probability of at least one.
Conditional Probability – A probability which is found considering the occurrence of a previous
event.
Dependent – When the outcome or occurrence of the first event affects the outcome or
occurrence of the second.
Disjoint (Mutually Exclusive) – Events that cannot occur at the same time.
Empirical Probability – The ratio of the number of times an event has occurred divided by the
number of observations of an activity that might cause the event to occur.
Equally Likely – Events that have the same probability.
Event – any outcome or set of outcomes.
General Addition Rule – P(A or B) = P(A) + P(B) – P(A and B)
Independence – When an event is not affected by the result of a previous event.
Multiplication Principle – The rule used to determine the number of ways an activity can occur if
it involves several successive parts.
Outcome – One of the simple individual occurrences of an activity.
Probability Model – a mathematical representation of a random phenomenon.
Random Phenomenon – Occurs when individual outcomes are uncertain, but there is nonetheless
a regular distribution of outcomes in a large number of repetitions.
Sample Space – The set of all possible outcomes.
Simulation – The imitation of chance behavior, based on a model that accurately reflects the
phenomenon under consideration.
Theoretical Probability – The expected ratio of the number of ways an event can occur to the
number of possible things that can happen.
Tree Diagram – A graphical representation of all outcomes.