2.145 Using MAD to measure variability The standard deviation is the most popular measure of variability from the mean. It uses squared deviations because the ordinary deviations sum to zero. An alternative measure is the mean absolute deviation, Σ• x - xQ • >n.

a. Explain why greater variability tends to result in larger values of this measure.

b. Would the MAD be more, or less, resistant than the standard deviation? Explain.