Data & Probability · Measures of center · 1.4

Range (spread).

The range measures how spread out the data is: subtract the smallest value from the largest. For 12, 4, 20, 9: 20 − 4 = 16. A bigger range means more spread.

01 / THE IDEA

See it work.

The data

See the values.

1214220394

Watch the method

Range (spread)

Range = maximum − minimum.

1 / 2
Find the range of: 12, 4, 20, 9.
1

Highest and lowest

Spot the maximum and the minimum.

max⁡=20, min⁡=4\max = 20,\ \min = 4
2

Subtract

Range is the spread: max − min.

20−4=1620 - 4 = 16
02 / YOUR TURN

Practice until it feels automatic.

Your turn

Work it out.

Type the answer — a fraction or decimal is fine.

streak 0
best 0

…

— / WHY IT WORKS

The idea underneath.

From low to high

The range is the gap between the extremes of the data.

Why it works

How far from smallest to largest?

03 / WORKED EXAMPLES

From easy to tricky.

EX 1easy

Find the range of: 14, 21, 30, 12, 6.

1

Highest and lowest

Spot the maximum and the minimum. max = 30, min = 6

2

Subtract

Range is the spread: max − min. 30 - 6 = 24

EX 2medium

Find the range of: 16, 10, 27, 21.

1

Highest and lowest

Spot the maximum and the minimum. max = 27, min = 10

2

Subtract

Range is the spread: max − min. 27 - 10 = 17

EX 3hard

Find the range of: 2, 9, 28, 15.

1

Highest and lowest

Spot the maximum and the minimum. max = 28, min = 2

2

Subtract

Range is the spread: max − min. 28 - 2 = 26

04 / COMMON TRAPS

Where students slip.

Trap

Confusing range with a center measure.

Fix

Range measures spread, not the average.

Trap

Subtracting in the wrong order.

Fix

Max − min (a non-negative number).

05 / QUIZ

Test yourself.

The Test

12 problems across three tiers. Auto-graded on submit. Hints and a full walkthrough on every question. Your work is saved on this device — sign in to keep it across devices.

0/12Answered
How to answerType just the value. Formatting won't trip you up — we ignore spaces, capital letters, commas, and subscript style, so t₁ = 5, d = 3 and t1=5,d=3 both count. For a list of numbers, separate them with commas (e.g. 3, 10, 17).
Core

Core (4)

C1

Find the range of: 4, 5, 4, 27, 12, 2.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
C2

Find the range of: 12, 17, 11, 30, 30, 12.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
C3

Find the range of: 4, 18, 27, 30, 5.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
C4

Find the range of: 19, 19, 30, 5.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
Apply

Apply (4)

A1

Find the range of: 28, 19, 16, 15, 8, 13.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
A2

Find the range of: 18, 11, 14, 26, 28.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
A3

Find the range of: 14, 23, 10, 9.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
A4

Find the range of: 21, 3, 28, 22, 17.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
Extension

Extension (4)

E1

Find the range of: 21, 24, 11, 21, 11.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
E2

Find the range of: 23, 17, 27, 14, 18, 24.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
E3

Find the range of: 11, 4, 21, 25, 24, 27.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.
E4

Find the range of: 16, 24, 14, 26, 17.

Need a hint?
  • Find the max and the min.
  • Subtract min from max.