In mathematics, an average, or central tendency of a data set refers to a measure of the "middle" or "expected" value of the data set. There are many different descriptive statistics that can be chosen as a measurement of the central tendency of the data items. The most common method is the arithmetic mean, but there are many other types of averages.The average is calculated by combining the measurements related to a group of people or objects, to compute a number as being the average of the gr… (More on Average)