From Central Tendency to Variability
This chapter has examined the three principal measures of central tendency in a set of values. Central tendency is a critically important attribute in any sample or population, but so is variability. If the mean informs you where the values tend to cluster, the standard deviation and related statistics tell you how the values tend to disperse. You need to know both, and Chapter 3, “Variability: How Values Disperse,” gets you started on variability.