How does the outlier affects the mean of the set of data? please help mee. ?

Question

How does the outlier affects the mean of the set of data? please help mee. ?

Answer 1

An outlier pulls the mean toward it.  Here is an example:

Take the set of data 1, 2, 3, 4, 5

The mean is 3

Now add the number 100 to the set

1, 2, 3, 4, 5, 100

Now the new mean is 115/6= 19.16666

see the addition of the 100 made the mean much higher.

If we would have added 9 to the data set instead of 100

1,2,3,4,5,9 the new mean would have been 24/6 or 4

since 9 is not an outlier it did not change the mean by much