# Excel: Finding deviation from mean

1. Sep 30, 2012

### Darth Frodo

Hi guys,

I have to find the deviation from the mean for each individual entry of a column of numbers.

Any one have any idea how to do this?

I'm clueless when it comes to excel

2. Sep 30, 2012

### Staff: Mentor

By deviation I'm assuming that you mean the difference from the mean. If you have already calculated the mean of the numbers in the column, then finding the deviation from the mean is simply a subtraction.

Suppose your numbers are in column A, in rows 1 through 20, and the mean of these numbers is in column A, row 25.

Starting in col. B, row 1, enter this formula: =A1 - $A$25
Don't omit the = that starts the formula. The dollar signs mean that if the formula is copied to another cell, the 2nd term will remain A25.
Next copy this formula and paste it into rows 2 through 20 of col. B.

If you haven't already calculated the mean, that's pretty easy, too. In col A, row 25, enter this formula: = AVERAGE(A1:A20)

3. Oct 1, 2012

### Darth Frodo

Thanks Mark, I bloody knew it involved \$s!