Hey guys, I have been pondering this since i was first introduced to it years ago in school so i hope one of you can shed some light on this. In a lot of root mean square formulas like the ones used in coordinate geometry, statistics and the rms formula in electronics, howcome we cant just square each number and square root it (to remove the negative sign) like for example ithe rms formula at http://en.wikipedia.org/wiki/Root_mean_square. Why do we have to find the square root of the demonimator? i have tried both ways and the result is always very very similar. to do it without square rooting the denominator just makes so much more sence to me according to my definition of what average is - the sum of all the different quantities and divided by the number of quantities. squaring and square rooting in each quantity just removes the negative sign. Thanks in advance! I cant wait to hear the reasoning behind this one!