1. Open Excel 2007 and select the 'Formulas' tab. Click the 'Statistical' button. A drop-down list appears.
2. Click 'Stdev.' The Standard Deviation function arguments window appears.
3. Type the first value in your standard deviation function in the 'Number 1' field. Type the second value in your standard deviation function in the 'Number 2' field. Click 'OK.' The standard deviation function is displayed in the cell.