Median lies at the middle part of the series and hence it is not affected by the extreme values. It is a special average used in qualitative phenomena like intelligence or beauty which are not quantified but ranks are given. Thus we can locate the person whose intelligence or beauty is the average. The mean cannot be calculated for categorical data, as the values cannot be summed. As the mean includes every value in the distribution the mean is influenced by outliers and skewed distributions. A mode is defined as the value that has a higher frequency in a given set of values. It is the value that appears the most number of times.