Probability Laws: Example #1

Objective: The purpose of this example is to learn the basic concepts and laws of probability. The following terms are used in this example:

  • Experiment: A process, consisting of one or more trials, of collecting data.
  • Trial: An action resulting in one of several possible outcomes.
  • Event: A set of related outcomes.
The following parts discuss how to compute: P(A), P(A and B), P(A or B), and P(A|B). Each part includes a Java Applet which demonstrates how the corresponding probability type is calculated. If you are new to probability, you should step through the parts in order.
  1. Single Event Describes how to compute the probability of a single event.
  2. Conditional Probabilities Computes the probability of one event given that the other event has occurred.
  3. Two Events: Multiplication (‘And’) Law Demonstrates how to compute the probability of the joint occurrence of two events.
  4. Two Events: Addition (‘Or’) Law Demonstrates how to compute the probability of the occurrence of one or the other (or both) events.