Basic probability

Basic probability

1. Mutually exclusive events

   • Two events are mutually exclusive if they cannot occur at the same time. Another word that means mutually exclusive is disjoint. If two events are disjoint, then the probability of them both occurring at the same time is 0.

2. Probability

   • The probability of an event is a measure of the likelihood that the event will occur. Statisticians have agreed on the following rules and conventions.
     • *The probability of any event can range from 0 to 1.
     • *The sum of probabilities of all sample points in a sample space is equal to 1.
     • *The probability of event A is the sum of the probabilities of all the sample points in event A.
     • *The probability of event A is denoted by P(A).

3. Event

   • An event is a subset of a sample space - one or more sample points .

4. Sample Space

   • A sample space is a set of elements that represents all possible outcomes of a statistical experiment .

5. Experiment

   • An experiment is a controlled study in which the researcher attempts to understand cause-and-effect relationships. The study is "controlled" in the sense that the researcher controls (1) how subjects are assigned to groups and (2) which treatments each group receives.