Sorry about that.

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:

- Obtain a two-sided confidence interval on a coefficient of variation of a normal distribution
- Obtain a one-sided lower confidence bound on a coefficient of variation of a normal distribution
- Obtain a one-sided upper confidence bound on the coefficient of variation of a normal distribution
- Obtain confidence bounds on the coefficient of variation of a lognormal distribution
- Perform a likelihood ratio test of the
hypothesis
that
*k*normally distributed populations share the same coefficient of variation - Obtain confidence bounds on a coefficient of
variation shared by
*k*normally distributed populations

The theory behind these programs is described in three publications:

- Confidence Bounds for Normal and Lognormal Distribution Coefficients of Variation, 2003, Research Paper 609, USDA Forest Products Laboratory, Madison, Wisconsin.
- Confidence Bounds and Hypothesis Tests for Normal Distribution Coefficients of Variation, 2007, Research Paper 638, USDA Forest Products Laboratory, Madison, Wisconsin.
- Verrill, S. and Johnson, R.A. (2007). "Confidence Bounds and
Hypothesis Tests for Normal Distribution Coefficients of Variation."
*Communications in Statistics -- Theory and Methods*, Volume 36, Number 12, pages 2187-2206.

For questions or comments about this Web page, please contact Steve Verrill at

Last modified on 9/9/09.

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