Question

Why is the standard deviation usually preferred over the​ range?

Answer 1

Standard deviations, σ, is generally preferred over range. Reason being, it is calculated from all the data and when there is outliers it will not be impacted as much as the range. It is great to not also that, The IQR is preferred to the standard deviation when the distribution is very highly skewed or when there are severe outliers, because the IQR is less sensitive to this features than standard deviation.