A multivariate extension of the exponentially weighted moving average (EWMA) control chart is presented, and guidelines given for designing this easy-to-implement multivariate procedure. A comparison ...

The harmonic mean is a type of numerical average used in investing to average multiples like the price-to-earnings ratio. It treats each value in a series equally.

Variance is a measurement of the spread between numbers in a data set. Investors use the variance equation to evaluate a portfolio’s asset allocation.

Before you take the P-Shot to your P (or your V), let's look at purported benefits, how much it may cost, who offers it, and what to expect after it's done.