Foundation and Higher · averages and range

Mean, median,
mode and range.
Which is which.

three averages,
one measure of spread

one number to stand for a whole set —

Average

mean · median · mode: a typical value

range: how spread out

step 1 of 4

Mean

1. Add them all up: 30.

2. Divide by how many there are: 5.

✓ Mean = total ÷ how many

3 + 7 + 4 + 7 + 9 = 30

30 ÷ 5 = 6

3

7

4

7

9

step 2 of 4

Median

1. Put them in order of size.

2. Find the middle one.

✓ Two middle values? Go halfway between

median = 7

in order first

3

4

7

7

9

step 3 of 4

Mode and range

1. Mode: the one that appears most often.

2. Range: biggest take away smallest.

✓ The range is one number, not “3 to 9”

mode = 7range = 9 − 3 = 6

3

4

7

7

9

step 4 of 4

Which average?

1. One extreme value drags the mean up.

2. The median is not affected by it.

✓ Outliers: use the median

233448

mean = 60 ÷ 5 = 12

median = 3

the median is more typical

averages and range —

Mean

add up, divide by how many

Median

middle value, in order

Mode

most common

Range

biggest − smallest

Comparing two sets? Compare an average
and the range, in context.

The
Maths Habit

Download The Maths Habit app
to test your knowledge