Median

The median is a simple measure of central tendency. To find the median, we arrange the observations in order from smallest to largest value. If there is an odd number of observations, the median is the middle value. If there is an even number of observations, the median is the average of the two middle values.

Thus, in a sample of four families, we might want to compute the median annual income. Suppose the incomes are $30,000 for the first family; $50,000, for the second; $90,000, for the third; and $110,000, for the fourth. The two middle values are $50,000 and $90,000. Therefore, the median annual income is ($50,000 + $90,000)/2 or $70,000.