The measure of center most affected by outliers is the mean. This is because outliers are very big or very small numbers that can change the average a lot.
For example, let's say we have these numbers:
3, 4, 5, 6, 7, 8, 9, 10, 11, 100.
If we find the mean, we add them all up:
3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 100 = 163.
Then we divide by 10 (because there are 10 numbers):
163 ÷ 10 = 16.3.
But if we look at the median (the middle number), we put them in order:
3, 4, 5, 6, 7, 8, 9, 10, 11, 100.
The middle numbers are 7 and 8. So, the median is:
(7 + 8) ÷ 2 = 7.5.
The mode is the number that appears the most. Here, there is no repeating number, so we can't find a mode.
So, the mean is 16.3, but without that big 100, the mean would be much lower! The mean changes a lot with the outlier, but the median stays around the same. That’s why the mean is most affected!