Forest Products Laboratory





A Confidence Interval on the Ratio of the Coefficients of Variation of Two Normally Distributed Populations


DISCLAIMER OF WARRANTIES

THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. THE AUTHOR (USDA FOREST SERVICE, FOREST PRODUCTS LABORATORY) DOES NOT WARRANT, GUARANTEE OR MAKE ANY REPRESENTATIONS REGARDING THE SOFTWARE OR DOCUMENTATION IN TERMS OF THEIR CORRECTNESS, RELIABILITY, CURRENTNESS, OR OTHERWISE. THE ENTIRE RISK AS TO THE RESULTS AND PERFORMANCE OF THE SOFTWARE IS ASSUMED BY YOU. IN NO CASE WILL ANY PARTY INVOLVED WITH THE CREATION OR DISTRIBUTION OF THE SOFTWARE BE LIABLE FOR ANY DAMAGE THAT MAY RESULT FROM THE USE OF THIS SOFTWARE.

Sorry about that.




What is the desired confidence level?
(95 for a 95% confidence level)


What are the two sample sizes?


What are the two sample means?


What are the two sample standard deviations?
(The sum of squares divisor in the standard deviation calculation should be n - 1 rather than n.)


What is the istart value for the random number generator?
(An integer between 1 and 1000000000)





This page is a form for calculating a confidence interval on the ratio of the coefficients of variation of two normally distributed populations. Here is FORTRAN source code for a standalone program that calculates the confidence interval.

We also have programs that do the following:

The theory behind these programs is described in three publications:




For questions or comments about this Web page, please contact Steve Verrill at sverrill@fs.fed.us or 608-231-9375.

[Forest Service] [Forest Products Lab] [FPL Statistics Group]


Last modified on 9/9/09.

As of last midnight, this page had been accessed times.