Symmetric datasets give us normal distribution curves, whereas asymmetric datasets give us skewed normal curves with different shapes of peaks. Asymmetric curves have non-zero skewness and kurtosis. In this article, we will show you how to create a graph of skewness and kurtosis in Excel effectively with appropriate illustrations.
Introduction to Skewness and Kurtosis
Skewness is a measure of the level of asymmetry in the distribution of a dataset. When a dataset is not distributed symmetrically, skewness is observed in the normal curve. An asymmetric normal curve can be positively or negatively skewed.
Kurtosis is the measure of tailedness in a normal distribution curve. It can help us find the outliers in a dataset. Based on the shape of the peak and tail, it can be platykurtic, mesokurtic, or leptokurtic.
How to Create Graph of Skewness and Kurtosis in Excel: 4 Easy Steps
In this article, we will demonstrate four easy steps to create a graph of skewness and kurtosis in Excel. We will use the following dataset for this purpose. The dataset contains a Student Name column and a Test Score column.
Step 1: Create Summary Statistics Table
In the first step, we need to create a Summary Table that contains Mean, Standard Deviation, Skewness, and Kurtosis.
- First of all, from your Data tab, go to,
Data → Analysis → Data Analysis
- The Data Analysis pop-up box will appear. Select Descriptive Statistics from there.
- Then click OK to open the Descriptive Statistics dialogue box.
- In the box, select the Input range (Test Score) from cells C5 through C20.
- Next, select the Columns and the Output Range.
- In the Output Range, select the cell where you want your Summary Statistics table to appear.
- Then check the box of Summary Statistics and click OK.
- Hence, the Summary Statistics table will appear in your desired cell.
Step 2: Calculate Bin Intervals
Now we will calculate bin intervals using the Mean and the Standard Deviation values.
- First, insert a column named Intervals.
- Next, select cell F5 and write down the following formula.
- Similarly, type formulas to cells F6 to F9 and determine Bin Intervals. All the formulas are given in the Formula column.
Read More: How to Calculate Skewness in Excel
Step 3: Determine Frequency
In this step, we will determine Frequency using the Histogram tool.
- First, go to Data >> Data Analysis.
- Then, select Histogram. A new dialogue box will pop up.
- In the box, select cells C5 through C20 as the Input Range.
- Then choose cells F5 to F9 as the Bin Range.
- Next, select Output Range to show Frequency in a specific cell and click OK.
- Consequently, you will get the Frequency for the Bin Intervals.
Step 4: Plot a Graph of Skewness and Kurtosis
Finally, it’s time to plot the graph of skewness and kurtosis. We will use the Charts tool for this purpose.
- Firstly, select the data of Bin Intervals and Frequency.
- Next, go to Insert >> Scatter and then select Scatter with Smooth Lines.
- Finally, you will have your graph of skewness and kurtosis.
- If you want to format the chart title, axis title, gridlines others, you can do this by using the Chart Design feature.
Download Practice Workbook
Download this practice workbook for practice while you are reading this article.
Thanks for making it this far. I hope you find this article useful. Now you know how to create a graph of skewness and kurtosis in Excel. Please let us know if you have any further queries and feel free to give us any recommendations in the comment section below.