Comments on: Harmonic Averages

By: Juan Carlos Méndez-García

Juan Carlos Méndez-García — Fri, 18 Jul 2008 10:15:20 +0000

More harmonic average examples on http://www.nerdblog.com/2008/01/harmonic-mean-mpg-standards.html

By: Juan Carlos Méndez-García

Juan Carlos Méndez-García — Fri, 18 Jul 2008 05:48:49 +0000

@Mathias - You are absolutely correct. I’ll fix the formula on the post to avoid confusion. Thanks very much for the Excel function. As you point out, Excel’s built-in HARMEAN() does not allow for weights.

By: Mathias

Mathias — Tue, 15 Jul 2008 06:54:03 +0000

It’s me again
Just to let you know that after reading this, I wrote a small Excel User-Defined function to compute the harmonic average… Makes it easier to use!
Cheers,
Mathias

By: Mathias

Mathias — Mon, 14 Jul 2008 08:11:23 +0000

Actually, I believe there is a typo in the formula in math notation; it should be Sum(UnitSold(i)) / Sum(UnitSold(i)/MPG(i))…

By: Mathias

Mathias — Thu, 10 Jul 2008 23:19:24 +0000

Thanks for the refresher! I remember learning about the 3 Pythagorean means way back in high school, but I don’t think I had seen the Harmonic mean mentioned since then. The Geometric mean comes up all the time if you work which growth rates (which is very common in financial calculations); it’s nice to have a good example of why the Harmonic matters, too!

By: Juan Carlos Méndez-García

Juan Carlos Méndez-García — Thu, 03 Jul 2008 23:26:20 +0000

Very easy to get confused… Bunnie is an uber-brilliant guy from MIT that has done wonders hacking hardware like the X-Box and others. I really admire his work.
On bunnie’s blog » Blog Archive » Miles per Gallon vs. Gallons per Mile you see:

Another seemingly more analytical approach also leads to the same conclusion: 50 + 18 MPG giving a 34 MPG household average seems more efficient than 34 + 28 MPG giving a 31 MPG household average.

Dude!!! Plain average or Weighted Average doesn’t work. You must use Harmonic Average when using ratios like MPG.