For each type of measure, I need two additional examples of populations where it would be the most appropriate indication of central tendency.
The mean is the arithmetic average, or simply the average, of a set of scores. You are probably more familiar with it than any other measure of central tendency. You encounter the mean in everyday life whenever you calculate your exam average, batting average, gas mileage average, or a host of other averages.
The median is a number that separates the higher half of a sample, a population, or a probability distribution from the lower half. More precisely 1/2 of the population will have values less than or equal to the median and 1/2 of the population will have values equal to or greater than the median.
The median is the middle score in a distribution of scores that have been ranked in numerical order. If the median is located between two scores, it is assigned the value of the midpoint between them (for example, the median of 23, 34, 55, and 68 would equal 44.5). The median is the best measure of central tendency for skewed distributions, because it is unaffected by extreme scores. Note that in the example below the median is the same in both sets of exam scores, even though the second set contains an extreme score. The mean is quite ...
This explains the Measures of central tendency-the mean, the median, and the mode