Calculate Mean and Standard Deviation With Excel 2007

Calculating the mean and standard deviation in Excel 2007 is as easy as 1, 2, 3 and only takes a few minutes.

Steps

Use the "AVERAGE" function in Excel to find the mean of a set of numbers. Enter the range of numbers in your Excel spreadsheet. Click where you want the mean (Average).
Click "Formulas" and select the "Insert Function" tab. Enter the numbers in your Excel spreadsheet in either a row or a column.
Scroll down and select the "Average" function.
Enter the cell range for your list of numbers in the number 1 box, for instance D4:D13 and click "OK"
The mean (average) for the list will appear in the cell you selected.

Use the STDEV function to compute the standard deviation. Place your cursor where you wish to have it appear.
Click on "Formulas" and select the "Insert Function" (fx) tab again.
Scroll down the dialog box and select the STDEV function.
Enter the cell range for your list of numbers in the number 1 box and click OK.
The standard deviation will appear in the cell you selected.

Once you become comfortable using these functions, you can skip the process of using the "Insert function" feature, and instead simply type the formulas directly into the cells as follows:
- Mean — "=AVERAGE(Cell range)" → e.g., "=AVERAGE(D4:D13)"
- Standard deviation — "=STDEV(Cell range) → e.g, "=STDEV(D4:D13)"
- Be sure to include the equal sign when using this method, as that is what indicates to Excel that what is contained in a cell is a formula.
When using older versions of Excel, you can do the same steps above by clicking on the Function Wizard (fx) button in the tool bar. Click on Statistical, Average or Statistical, then STDEV.