How Do I Create Boxplots in Excel Using SigmaXL?

Box Plots

1. Click Sheet 1 Tab of Customer Data.xlsx (or press F4 to activate last worksheet).



2. Click SigmaXL > Graphical Tools > Boxplots.



3. Ensure that entire data table is selected. If not, check Use Entire Data Table. Click Next.



4. Select Overall Satisfaction, click Numeric Data Variable (Y) >>, select Customer Type, click Group Category (X1) >>, check Show Mean, check Show Legend:





5. Click OK. A boxplot of Customer Satisfaction By Customer Type is produced:





6. The legend indicates that the solid center line is the median. The dashed red line shows the sample mean. The top of the box is the 75th percentile (Q3). The bottom of the box is the 25th percentile (Q1). The height of the box is called the Inter-Quartile Range (IQR) and is a robust measure of spread or sample variability. The data point highlighted for Customer Type 2 is a potential outlier (< Q1 – 1.5 * IQR or > Q3 + 1.5 * IQR). Note that extreme outliers are highlighted with a solid dot (< Q1 – 3 * IQR or > Q3 + 3 * IQR).

Tip: If you hover your mouse cursor in the middle of any of the Boxplot lines as shown, you will see the balloon help indicating what the line is and its numeric Y value.

7. Now we will modify the Y axis scale, showing 1 as minimum and 5 as maximum (given that the response data comes from a survey with 1-5 scale). To do this right click on the Y axis and select “Format Axis”, modify the minimum value and maximum value. Change Horizontal axis crosses > Axis value to 1 as shown:






8. The Boxplot axis is modified as shown below:





9. Click Recall SigmaXL Dialog menu or press F3 to recall last dialog.



10. Select Overall Satisfaction, click Numeric Data Variable (Y) >>; select Customer Type, click Group Category (X1) >>; select Size of Customer, click Group Category (X2) >>; check Show Mean; uncheck Show Legend:





11. Click OK. Boxplots of Customer Satisfaction By Customer Type and Size are produced:






12. In order to adjust the Y-axis scale for both charts, click SigmaXL Chart Tools > Set Chart Y-Axis Max/Min.
    
    
    
    
13. Click OK. The Y-axis scale maximum and minimum are now modified for both charts.