Microsoft Office Tutorials and References

In Depth Information

Computing Standard Deviation

A common calculation in many statistical and distribution analysis is the standard deviation.

For example, you might want to calculate the standard deviation from the mean price.

Because the standard deviation is not an easy formula to compute, we show you an example

with a few values so that you can better understand the formula.

Let us start with a very simple set of values, divided into two periods in time, as you can see

in Figure 9-7. You can find this example in the CH09-03-StandardDeviation.xlsx workbook

included on the companion DVD.

FIguRE 9-7
Sample data for the standard deviation calculation.

You can easily import the data into PowerPivot, and then after you add a calculated measure

that computes the AVERAGE of Value, you can perform the first simple analysis, shown in

Figure 9-8.

FIguRE 9-8
Simple analysis of the average value over periods.

Standard deviation shows how much variation there is from the average. In other words, it is

an indicator of how far the values are from their mean.