Quantile-Quantile (QQ) Plot

In statistics, a Q-Q Plot (“Q” stands for Quantile) creates a graphical comparison between two distributions by plotting their quantiles against each other.


NumXL provides an intuitive interface to help Excel users construct a Q-Q Plot of an empirical sample data distribution against a theoretical Gaussian distribution. In this tutorial, we’ll demonstrate the steps to construct a Q-Q Plot using NumXL functions in Excel.

  1. Select an empty cell to store the histogram table
    Select an empty cell in the Excel worksheet to place the histogram output table.
  2. Locate the Descriptive Statistics (DESC STAT) icon in the toolbar (or menu in Excel 2003) and click the down-arrow. When the drop-down menu appears, select “Q-Q Plot”
    Q-Q-Plot icon in the NumXL toolbar.
  3. The Q-Q Plot dialog box appears
  4. Select the cell-range for the input data
    NumXL QQ-Plot Wizard dialog box in Excel.
    Note: The table output range is set to the selected empty cell in your worksheet.
  5. Next, select the number of quantiles (number of points in the Q-Q Plot). The number of bins is set initially to 10.
  6. Click OK.


The QQ-Plot wizard generates the output table and plots the graph on the right.
Q-Q-Plot table and accompanying graph generated by the NumXL Wizard in Excel.


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