If you took out the outlier, (25) the mean would change because to find the mean you add the numbers together and then divide the total you get by the amount of numbers presented. With the outlier: 70 divided by 7 = 10 Without the outlier: 45 Divided by 6 = 7.5. As you can see, there is a difference of 2.5 if you take the outlier away.