Which term describes the middle number in a series of numbers listed in order?

The term that describes the middle number in a series of numbers arranged in order is the median. To find the median, one organizes the numbers from smallest to largest and identifies the value that falls exactly in the center. If there is an odd number of values, the median is the number that has an equal count of values on either side. In cases where there is an even number of values, the median is calculated by taking the average of the two middle numbers.

This definition is important in statistics, as the median provides a measure of central tendency that is not affected by outliers or extreme values, making it particularly useful in a wide range of data analyses. The mean, for instance, can be skewed by very high or very low numbers, whereas the median will remain stable. Understanding these concepts is crucial for correctly interpreting data sets in psychology and various other fields.