Variance, Standard Deviation, and Coefficient of Variation

Free SOA Exam P (Probability) lesson in Univariate Random Variables. 17 min read, ~2,560 words.

Variance shortcut:; always compute each piece separately. Scaling rule:; the constant drops out, the coefficient squares. Standard deviation is and carries the same units as. CV =: dimensionless and invariant to positive scaling. Exponential: CV = 1 always; Poisson: mean = variance =; Uniform:. Chebyshev: at least of probability lies...