other means n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Other Means PowerPoint Presentation
Download Presentation
Other Means

Loading in 2 Seconds...

play fullscreen
1 / 13

Other Means - PowerPoint PPT Presentation


  • 121 Views
  • Uploaded on

Other Means. The Geometric Mean The Harmonic Mean. Arithmetic and Geometric mean differences. A few examples…. Population calculations – in calculations involving populations, the population size must be multiplied by the factor of increase – thus we use the geometric mean.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Other Means' - stacie


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide2
The Geometric Mean
  • The Harmonic Mean
a few examples
A few examples…
  • Population calculations – in calculations involving populations, the population size must be multiplied by the factor of increase – thus we use the geometric mean.
using the book example of calculations of a population of mule deer
Using the book example of calculations of a population of mule deer:

The arithmetic mean tells us that in a population of 1000 deer increasing 10% one year and 20% the next, the average increase is 15%. However, this gives us 1322.5 deer when the actual population increase is to 1320 deer.

if we use the geometric mean instead the calculations are as follows
If we use the geometric mean instead, the calculations are as follows…

10% and 20% increase is the same as 1.10 and 1.20

Take the natural log of these to get:

ln(1.10) = 0.09531 and ln(1.20) = 0.18232

The arithmetic average of these two is 0.138815

(.09531 + 0.18232 / 2 = 0.138815)

Take the antilog of the arithmetic mean:

e 0.138815 = 1.14891

Multiply this by the population size each year to get a total end population of 1319.99 – closer to the 1320 actual deer.

other ways to calculate geometric mean
Other ways to calculate geometric mean:
  • There are a couple of ways to get the geometric mean…
  • One is to take the antilog of the arithmetic mean as we just did
  • Another is to take the nth root of the product of the observations (or the 1/nth power of the product of the observations which we’ll try in the next example)
another example
Another example…
  • Rates of return on investments – When calculating the amount of return on an investment you would again use the geometric mean to determine what constant factor you would need to multiply by – this should give you the average interest rate.
slide9
If we had an investment that returned 10% the first year, 60% the second, and 20% the third what is the average rate of return? (not 30%!)

To calculate this, remember 10, 60, and 20 percents are the same as multiplying the investment by 1.10, 1.60, and 1.20.

To get the geometric mean calculate:

(1.10 x 1.60 x 1.20)1/3 = 1.283 or an average return of 28% (not 30%!)

the harmonic mean
The Harmonic Mean

One way of discussing the harmonic mean (H), is with reference to the arithmetic mean (A) and the geometric mean (G)…

In this way we could say that

slide11
Or…
  • We could get the harmonic mean by:

Taking the number of terms (n) in a setand dividing it by

The sum of the terms’ reciprocals

So with set (a1,...,an )

slide12
The arithmetic, geometric, and harmonic means are related in the following way:

the arithmetic mean > the geometric mean > the harmonic mean

Unless the terms of the set are equal in which case the harmonic, arithmetic, and geometric means will all be the same.

in summary
In Summary:
  • When calculating with a set containing only two terms the

arithmetic mean is:

the geometric mean is:

and the harmonic mean can be: