Tutor’s Toolkit: Application of Number

Carrying Out Calculations

C9	Use range to describe the spread within sets of data

C9.1	Range

Scope: 

Students need to be able to:
•	Calculate the range of a set of data given as a list.
•	Calculate the range of a set of data taken from a table.

What students need to know:

Calculate the range of a set of data given as a list.

The range tells you how spread out the data is. Two different companies may have the same mean average wage. However, the wages in one may be very spread out (The boss earns a fortune and the cleaners are paid a pittance), while wages in the other company are not spread out (the boss earns a little bit more and the cleaners a little bit less than everyone else). We can then make a fair comparison between these two firms.

The range is the largest value take away the smallest value.

Example Question:
What is the range of this set of student’s heights:
1.65m, 1.87m, 1.48m, 1.84m, 1.76m, 1.79m, 1.81m, 1.56m.

Solution:
The tallest is 1.87m and the smallest is 1.48m.
So, the range is 1.87 – 1.48 = 0.39m.

Calculate the range of a set of data taken from a table.

Example Question:
What is the range of temperature during the week?

Day	
Temperature	

Mon	
3C	

Tue	
7C	

Wed	
12C	

Thur	
5C	

Fri	
1C	

Sat	
3C	

Sun	
1C	

Solution:

The highest temperature is 12C and the lowest temperature is 3C.
So, the range is the difference between these two amounts:
12C – 3C = 15C.