Skewness

Skewness indicates whether the data is spread symmetrically or is concentrated on one side of the graph. There are three different types of skewness:

• Positive skew
• Negative skew
• Zero skew

Correctly calculating the skew is quite complex, so we'll focus on understanding the skew, since Python and R have a way to calculate the skew for us correctly. As SQL Server is not a statistical tool, it does not have any built-in function for direct skewness calculation. But we can define the skewness based on the central tendency measures of mean and median:

• If the mean > median, then you'll observe the positive skew.
• If the mean < median, then you'll observe the negative skew.
• If the mean = median, you have zero skew: