Class Interval | Statistics

The class interval is the width of a class, the class interval is the difference between the maximum limit for the class and the lowest limit for the class.

When data are organized in classes, all classes have equal class intervals. The first and the last class may, however, be open. The class interval can be determined by using the formula:

Class interval > ((maximum value - minimum value) / number of classes)

Class intervals should be in whole numbers (integers) and even numbers. A class limit that not is an even number should be rounded up.