Frequency Distribution

It is not only important to understand what descriptive data represent but, if possible, to see it as well. One way to do this is through the use of a frequency distribution, a visual representation of a distribution of data.

Table 1 shows 25 scores on a math test for which a frequency distribution will be created.

The first step in creating a frequency distribution is to define the class interval that will be used. A class interval is a range of numbers, and the first step in the creation of a frequency distribution is to define how large each interval will be.

Some guidelines for creating a class interval are as follows:

• 1.
  Select a class interval that has a range of 2, 5, ...