Content

• To step

This wikiHow teaches you how to calculate the standard error of an average in Excel. You calculate the standard error by dividing the standard deviation (σ) by the square root (√) of the sample size (N).

To step

1. Open Excel. This is the app with a green icon that represents a spreadsheet with an "X" on it.
2. Open or create a new Excel document. If you already have an Excel spreadsheet with your data, you can open it by clicking "Open" in the green bar on the left. Otherwise you can create a new document by clicking on "New" and enter your data here.
3. Find the standard deviation. Although calculating standard deviation usually requires a few math steps, you can calculate standard deviation in Excel by typing in the following formula = stdev ("cell range").
   • For example, if your data is in cells A1 through A20, type = stdev (A1: A20) in an empty cell to obtain the standard deviation.
4. Enter the standard error formula for the mean in an empty cell. The formula for calculating the standard error of the mean in Excel is = stdev ("cell range") / SQRT (count ("cell range")).
   • For example, if your data is in cells A1 through A20, you can type the following formula in a blank cell to calculate the standard error of the mean = (stdev (A1: A20)) / SQRT (count (A1: A20)).