The more data we have, the more information we have. But it is difficult to comprehend large collections of numbers. Two methods are used to improve such understanding. These are numerical, and graphical descriptions of data.
Graphical descriptions are visually more pleasing, but are also harder to make.
Numerical descriptions, when used and interpreted properly, provide almost as much qualitative understanding as visualization methods. Mathematicians have invented many methods of computing averages. The three most important measures of the center used in statistics are the median , the mode and the mean . Median The median of a collection of data values is a number that is greater than half the values and less than the other half. If there are an odd number of values, the median is the middle one when they are sorted in order of magnitude.