# Harmonic mean explanation needed?

• Aug 20th 2012, 01:11 PM
hisajesh
Harmonic mean explanation needed?
Why do we need harmonic mean , how it can give better precision in specific situations. Please justify situations where harmonic mean is better than arithmetic mean.
• Aug 20th 2012, 02:24 PM
pickslides
Re: Harmonic mean explanation needed?
Arithmetic mean is sensitve to outliers. Therefore the harmonic mean can be a better estimate of central tendancy in a skewed distribution.
• Aug 20th 2012, 02:50 PM
hisajesh
Re: Harmonic mean explanation needed?
Let's look at this problem?
A Car going to and fro @ 4km/hr , 3 km/hr and 5km/hr.
In this case, arithmetic mean gives 4 km/hr and harmonic mean gives 3.82..km/hr.
Though defitintion sugeests harmonic mean should be used when distance is the same and different speeds.
How do you justify 3.82 (harmonic mean)is a more exact average than 4(arithmetic mean.)
• Aug 22nd 2012, 03:04 AM
HallsofIvy
Re: Harmonic mean explanation needed?
That last post is simply spam with non-sense added as a first paragraph. This forum is becoming riddled with spam. Where are the moderators??