is the "standard" average, often simply called the "mean". = {1 \over n} \sum_{i=1}^n{x_i}" src="http://upload.wikimedia.org/math/a/6/5/a65756f8749e6d0ca0223d4f4a1ab265.png"> The mean may often be confused with the median or mode . The mean is the arithmetic average of a set of values, or distribution; however, for skewed distributions, the mean is not necessarily the same