Glossary
range
The range of a data set is the difference between its largest and smallest values — subtract the smallest from the largest. It is a measure of spread, not of center.
The range of a data set is the spread between its extremes: take the largest value and subtract the smallest. For 12, 7, 19, 4 and 15 the range is 15 (19 − 4). It is the simplest measure of how spread out the values are.
It is easy to confuse with the two nearest ideas. The range is not the largest value, so answering 19 above is a miss. It is not the average either — mean, median and mode describe the center of a set, and the range describes how far the set stretches. Read the question for whether it wants a center or a spread.
Because the range depends on only two numbers, one extreme value can change it completely, which is the point a question often makes: adding an outlier to a set barely moves the median and can double the range. When a problem gives you a range and asks for a missing value, the pieces rearrange the same way — largest minus smallest equals the range, so the missing value is either the range added to the smallest or taken from the largest.
Taught in
Related terms
- median — The median is the middle value of a set of numbers once they are in order. Half the values lie below it, half above, and it is not moved much by an outlier.
- mode — The mode is the value that appears most often in a set of numbers. A set may have one mode, several modes, or no mode if every value appears once.
Source: Official ASVAB — subtest descriptions (what each subtest asks) and the CAT-ASVAB scored-question counts (accessed 2026-09)