Discrete variables

Again, we have met several examples of discrete random variables in probability. Discrete variables are also numerical within a countable range. Some examples of discrete variables include

• year;

• number of students in a class;

• number of questions answered correctly on a test;

• performance score.

• finishing position in a race.

Notice that many examples of discrete variables involve counting, of the form ``number of \(\ldots\)““. Discrete variables can be included in a regression model on the continuous scale or as a categorical variable. The main thing to consider is the natural ordering of discrete data.