median

n. The median is a measure of central tendency that is located at the center of a distribution of scores that have been ranked in numerical order. For example, the median in the distribution of ages 18, 18, 19, 23, and 24 is 19 because it occurs at the midpoint of the group of values. Half the values occur above and half occur below 19. If the distribution has an even number of scores, the median is the average of the two middle scores. For example, the median of 18, 18, 19, 23, 24, and 27 is 21. The median is unaffected by extreme scores and is the best measure to use for skewed distributions, such as annual income, in which a small number of scores may be extremely high. For example, in the distribution of hourly wages $13, $15, $15, $17, and $350 the median would be $15 an hour.

-DS