How_To_Be_Good_At_Math

280 STATISTICS •^ THE RANGE

Let’s find the range of our

giraffes’ heights. First,

we’ll write down their heights

in order, from shortest to

tallest. This gives us:

2.8, 2.8, 3.7, 3.8, 4.4

So, the range of the

giraffes’ heights is 1.6 m.

Now let’s find the shortest

and tallest heights.

These are 2.8 m and 4.4 m.

Next, subtract the shortest

height from the tallest.

This gives 4.4 − 2.8 = 1.6

The range

The spread of values in a set of data is known as the range.

It’s the difference between the smallest and largest values in the

set. Like averages, the range can be used to compare sets of data.

2.8 m 2.8 m

Roll the dice, find

the average

Don’t worry if you

haven’t got a group

of giraffes handy to

help you understand

averages; you can use

dice instead. For these

investigations, all you

need is two dice.

RANGE

3.7 m

4.4 m

0

4 m

3 m

5 m

2 m

Roll both dice.

Write down the

total number of spots.

What if you roll the dice 20 times? Do you get

the same mean, mode, median, and range?

Do this 10 times.

Calculate the mean and find the mode,

median, and range for the dice rolls.

TRY IT OUT

HEIGHT

3.8 m

To find the range,

subtract the smallest

value from the largest.

The result is the range.

1 m

280_281_Range_using_averages.indd 280 29/02/2016 18:06