Print

Appendix E: Using Excel to Calculate the Average and Standard Deviation

Excel can be used to calculate the average value of a set of measurements and the standard deviation. To use Excel for this purpose, follow these steps.
1
Enter the readings in the first column. In this example, the values entered in cells A3 to A7 are the height (in inches) of five students (see Fig. 1 below).
Figure 1

Figure 1: Entering your data

2
In cell A8 type = and select AVERAGE from the pull-down menu (see Fig. 2 below).
Figure 2

Figure 2: Selecting from the pull-down menu

3
The Functions Argument window with A3:A7 in the Number 1 field is displayed as shown in Fig. 3 below.
Figure 3

Figure 3: Finding the average value

4
Select OK. The average of the five values is displayed.
Figure 4

Figure 4: Average value is displayed

Alternately, you can combine steps 2, 3, and 4 by typing = AVERAGE(A3:A7) and pressing ENTER.
5
In cell A9, type = and select STDEV from the pull-down menu. The Function Argument window is displayed.
Figure 5

Figure 5: Finding the standard deviation

6
Excel automatically calculates the standard deviation of the five heights and the average. To input the correct range, click the icon to the right of the Number 1 field and select cells A3 through A7.
Figure 6

Figure 6

7
Click OK. The standard deviation is displayed.
Figure 7

Figure 7