The range tells you how spread out the data is. It is not an average — it measures the distance between the largest and smallest values.
Example 1 — Range of 4, 9, 2, 7, 11, 5
Step 1
Maximum = 11, Minimum = 2
Step 2
Range = \(11 - 2 = \mathbf{9}\)
Example 2 — Test scores: 55, 62, 78, 45, 90, 68
Step 1
Max = 90, Min = 45
Step 2
Range = \(90 - 45 = \mathbf{45}\) marks
Step 3
A range of 45 marks shows the scores are quite spread out.
Common mistake: The range is not an average — never write "the range is 9 so the typical value is 9". The range only tells you how spread out the data is.
✓ Quick Check 1 — Calculating the range
Question 1 of 10
Using Range in Context — Comparing Consistency
A small range means the data is consistent (close together). A large range means the data is spread out (variable). The range is often used to compare two groups.
Example 6 — Golf scores (under par is negative): −4, −2, 0, 3, −1, 5
Step 1
Max = 5, Min = −4
Step 2
Range = \(5 - (-4) = 5 + 4 = \mathbf{9}\) strokes
Step 3
A range of 9 strokes shows inconsistent scoring.
Common mistake: Students write Range = Max − |Min| without flipping the sign. Remember: subtracting a negative is the same as adding its positive value.
✓ Quick Check 3 — Range with negatives and real-life context
Question 1 of 10
Try It: Range Summary
Key range calculations to verify your understanding.
#
Data
Range
1
4, 9, 2, 7, 11
9
2
−3, 5, −8, 10
18
3
Team A: 78,80,82 (range?)
4
4
Team B: 55,90,40,95 (range?)
55
5
6, 6, 6, 6
0
Practice: Finding the Range
Enter your answers as numbers.
#
Question
Answer
Result
1
Find the range of 4, 9, 15, 3, 22
2
Find the range of 55, 60, 48, 72, 65
3
Find the range of 100, 100, 100, 100
4
Find the range of −5, 3, 8, −2
5
Find the range of 12.5, 9.2, 15.8, 7.1
6
Find the range of 30, 45, 20, 60, 35
7
Find the range of −8, 2, −3, 6
8
Find the range of 200, 350, 275, 400
9
Find the range of 1.5, 2.8, 0.9, 3.2
10
Find the range of 7, 21, 14, 3, 28
⚠ Things to Watch Out For
Thinking range is an average: Range is a measure of SPREAD, not an average. It tells you how spread out the data is, not what a typical value is.
Subtracting maximum from minimum: Range = MAXIMUM − MINIMUM (not the other way round). The range is always positive.
Including outliers: The range is heavily influenced by outliers. One very large or very small value dramatically increases the range — this may not represent the typical spread.
Range with negative numbers: Range of {−5, −2, 3, 7} = 7 − (−5) = 12 (subtract a negative = add). Don't write 7 − 5 = 2.
Range tells you nothing about distribution: Two data sets can have the same range but very different distributions. Range alone doesn't describe how spread out the data is within that range.