Descriptive Statistics Part II: Central Tendency and Variability 1 Briefly discuss the concept of mode, mean, median. What is it? How is it calculated? When would we use each one? * MeanThe mean is also loosely referred to as the average. The arithmetic mean or simply the mean is calculated by summing up all the values and then dividing the result by the total number the total number of quantities available (Regentsprep.org, 2012). The total number of quantities within the set of values is referred to as the frequency.