When all the values in a data set are written in order from least to greatest the value that is in the middle with an equal number of values below it and equal number of values above?

The value that is in the middle of a data set when arranged in order from least to greatest is called the median. If there is an odd number of values, the median is the middle number. If there is an even number of values, the median is the average of the two middle numbers. The median is a useful measure of central tendency that is less affected by outliers than the mean.