A measure of center<span> is a value at the </span>center<span> or middle of a </span>data set. Graphically, the center<span> can be viewed as the "balance point" of the display. Algebraically, the most common ways to find the </span>center<span> are with the mean, median, or mode. Mean is the average or sum of all </span>data<span> points divided by the number of points.</span>
The center<span> of a data set is a single number that we can use to stand in for the whole data set. You can usually think of it as a "typical" value. We usually use </span>mean<span> or </span>median<span> for the center. The median is often a better "typical" value if the distribution is skewed (that is, grossly asymmetrical).</span>