Definition
Range of data
The greatest data value minus the least data value.
What it means
Find the two ends of the data: the least value and the greatest value. Subtract the least from the greatest. The answer tells how far apart the extremes are; it does not describe what happens between them.
Remember it
Range is the gap from the data’s low end to its high end.
Example
For the data 4, 6, 6, 9, 15, the least value is 4 and the greatest is 15. The range is 15 − 4 = 11.
Watch for
The range is not the number of values in the data set, and it is not the list of possible outputs of a function.
Common mix-up
One unusually high or low value can change the range a lot because only the two extremes are used.
Exact meaning
The range of a numerical data set is its maximum value minus its minimum value, giving a simple measure of spread based only on the two extremes.