A First Course in Quality Engineering, 2nd Edition

Statistics for Quality 69

2.5.1.2  Computing the Probability of an Event

There are two basic methods for computing the probability of events:

1� Method of analysis of experiment

2� Method of relative frequency

The rst method is used when we know, from an understanding of the

experiment, the relative chance for occurrence of the outcomes� The second

method is used when we do not know the relative chance for the occurrence

of the outcomes� Use of these methods is illustrated in the examples below�

A third method, which involves subjectively assigning probability values to

events based on one’s prior experience with such events, is also available�

Such probabilities are used in a branch of statistics known as “Bayesian sta-

tistics�” Bayesian ...