Constructing a relative frequency histogram:

1. Choose the number of classes, usually between 5 and 10.

2. Calculate the approximate class width by dividing the difference between the largest and smallest values by the number of classes.

3. Round the approximate class width up to a convenient number.

4. If discrete, assign one or more integers to a class.

5. Locate the class boundaries.

6. Construct a statistical table containing the classes, their boundaries, and their relative frequencies.

7. Construct the histogram like a bar graph.

©1998 Brooks/Cole Publishing/ITP