Estimating Variance Simulation

Prerequisites
Measures of Variability

The average squared difference from the sample mean will, on average, underestimate the population variance. In some samples it will overestimate it, but most of the time it will underestimate it. If the formula is modified so that the sum of squared deviations is divided by N -1 rather than by N, then the tendency to underestimate the populationvariance is eliminated.