# Is there name for arithmetic mean divided by RMS average?

Is there a mathematical term for the ratio of arithmetic mean to the root mean square average?

(FWIW, in the context where I'm concerned about this the component values will always be >= 0.)

-

It's not quite the coefficient of variation, but there's an algebraic relation along the lines of $\sqrt{1-(\frac\sigma\mu)^2}$ (though the signs in that expression come out differently each time I try to derive it, so caveat lector!) – Henning Makholm Aug 22 '12 at 16:40
To be more accurate, the quantity that OP is interested in is equal to $1/\sqrt{\text{COV}^2+1}$, or $\cos(\arctan( \text{COV}))$ – Erick Wong Aug 22 '12 at 16:41