The following are the kids of variations used in SIX Sigma:

Mean: The variations are measured and compared using the averaging techniques of mathematics. The measures are taken for a specific application and the mean is calculated

Median: The variations are measured and compared using the mid point in a given range of data. It is measured by finding the highest and lowest value then dividing it by two. The lowest value is added to the same

Range: The values of a specific data range. It is the difference between highest and lowest values in a specific data range.

Mode: Mode is the most occurred values in a given data range.