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Chapter 8: Discrete Probability Distributions
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Figure 8-3:
Discrete Possibilities for the Number of Absences
Next, we will define what we mean by a continuous random variable.
Definition: Continuous Random Variable
A continuous random variable is one that can assume any value in an
interval on the real number line.
For example, the amount (in inches) of rainfall in your community during
the month of March is an example of a continuous random variable. If
X
is
the amount it rained during the month of March, then the possible values
will be in the interval [0,
). That is, the amount can vary from zero inches
to an infinite number of inches. Theoretically, the number of inches of
rainfall can go to infinity (
), but from a practical standpoint, this may never
happen. A practical continuous interval may be [0, 6] inches as shown in
Figure 8-4
.
Figure 8-4
: Continuous interval of rainfall
Note:
We will deal only with discrete random variables in this chapter.