**Authors:** Sabiou Inoua

This short paper establishes one more formula for the variance. Consider a random variable *X* whose possible values are *x*_{1}, …, *x*_{n} with probabilities *p*_{1}, …, *p*_{n} of occurring, respectively. Pick two of these possible values
successively (each *x*_{i }having the probability *p*_{i} of being chosen). Compute the difference between the two chosen
values. Square the difference. Claim: you are expected to get (twice) the variance of *X*. This formula makes the variance appear an even more
natural measure of dispersion than usually thought.

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[v1] 2013-06-05 07:25:19

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