Question

Which one of the tools of dispersion seems to be the best one to use between the range, variance and standard deviation? What is the benefit of know how spaced the scores are in an analysis?

Answer 1

Standard deviation is the best among range and variance .Since variance is the square of standard deviation so it is in squared units of the data whereas standard deviation is in the as units as the data so its better than variance.As far as range is considered its values is not very stable from sample to sample as it depends on the two extreme values of the data and not on each and every observation of the data.

Benefits of how much spaced the scores are as