About this lesson
Basic Statistics in Excel
Descriptive Statistics provide the metrics to determine if data is normal. This lesson shows how to install the Data Analysis Add-in to the Data Ribbon and how to use the this add-in to calculate descriptive statistics for a data set. The Data Analysis add-in will be used in future lessons.
When to use
Use Descriptive Statistics to provide basic information about a data set. It can also provide information to assess whether a data set is normal.
Throughout this course we will be working with data sets and it is faster to use the Excel Descriptive Statistics function to obtain the information about a data set at one time than it is to calculate each of the items individually.
The Descriptive Statistics function is found on the Data Analysis Menu in the Data Ribbon. If your version of Excel does not have the Data Analysis menu showing at the right edge of the Data Ribbon, then you will need to activate it.
- Go to the File menu and select Options.
- On the Options menu, select Add-ins.
- In the Add-in window, select Analysis ToolPak and click on OK.
- The Data Analysis menu item should now be in your Data Ribbon.
To generate the data set metrics, use the Descriptive Statistics function.
- Select the Data Analysis menu from the Data Ribbon.
- Select Descriptive Statistics from the Data Analysis list of functions.
- Enter the location of your data set in the Input Range field.
- Select the location of where you want Excel to place the results from the Output Options.
- Select Summary Statistics and click OK
The summary statistics are similar to those we have discussed in other modules. However, two are helpful when determining normalcy. Skewness is the measure of whether the data is centered or the majority of the data is off to one side or the other of the mean. It is a measure of symmetry. A normal curve has a skewness value approaching zero. Kurtosis is a measure of how heavy the tails of the data set are as compared to the center. It is sometimes thought of a measure of peakness. A normal curve has a Kurtosis of 3. However, Excel is showing the Kurtosis Excess. This is the Kurtosis value minus 3. Because of this, a normal curve in the Excel Descriptive Statistics function will have both skewness and Kurtosis that are near zero.
Hints & tips
- I prefer to show my Descriptive Statistics on the same worksheet as the data so that I don’t confuse the data sets.
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