Mean

A statistical term which is the average value in a set of numbers. The mean is the sum of a set of numbers divided by how many numbers are in the set.

For example, if we measure the tumour sizes of five patients and calculate the mean, we get an idea of what the average tumour size is across that group – which can help doctors spot patterns or compare treatments.

For example, in the following dataset:

• 2, 4, 6, 8, 10.
• The mean is 6 (2+4+6+8+10= 30. 30/5=6)