σ - Standard deviation of article prices (% from average price)

The σ value is represented in the application according to the tooltip description as: standard deviation of article prices (% from the average price). We calculate this value based on the arithmetic mean of the lowest and highest prices shown in the Products module:

Then, using the difference between the unit price of each offer and the average, we calculate the deviation value. We present the result as a percentage to make the data more transparent.

The interpretation is as follows:
The lower the deviation, the smaller the spread of prices around the average.
The higher the deviation, the wider the spread of prices between the cheapest and the most expensive offer.

Based on the example below, the calculation would be:

• Mean: 43.41

• Number of offers in the ranking: 3

• Standard deviation: 24.46

• Standard deviation of article prices (% from the average price): 24.46 / 43.41 = 56.33%