PS296 Chapter Notes - Chapter 7: Mutual Exclusivity
3 Views of Probability:
Analytic view of probability:
-oldest and most common definition
-if an event can occur in A ways and can fail to occur in B ways, and if all possible ways are
equally likely, then the probability of its occurrence is A/(A+B)
-the probability of its failing to occur is B/(A+B)
Frequentist view:
Replacement:
-ex each M&M is replaced before the next one is drawn
-probability is the limit of the relative frequency of occurrence of the desired event that we
approach as the number of draws increases
-probability is defined in terms of past performance
Subjective probability:
-probability represents an individual's subjetive belief in the occurrence of something
-may have no mathetmatical basis whatsoever
-most people use the different approaches interchengeable
Document Summary
If an event can occur in a ways and can fail to occur in b ways, and if all possible ways are equally likely, then the probability of its occurrence is a/(a+b) The probability of its failing to occur is b/(a+b) Ex each m&m is replaced before the next one is drawn. Probability is the limit of the relative frequency of occurrence of the desired event that we approach as the number of draws increases. Probability is defined in terms of past performance. Probability represents an individual"s subjetive belief in the occurrence of something. Whenever you speak of a probability of something, the something is called an event. When occurence of one has no effect on occurence of another. Occurence of one event precludes the occurrence of the other. Ex first year, sophomore, junior and senior are mutually exclusive bc you cannot be a member of more than 1. If a set of events includes all possible outcomes.
