Re: Coefficient of variation From: Marilyn Whitney (riparian@ncal.net) Date: Sun May 11 2003 - 18:20:50 PDT Next message: Marilyn Whitney: "ARE 157 exam coverage, MTM 2" Previous message: Marilyn Whitney: "oops, disregard last message!" Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] -------------------------------------------------------------------------------- "I am having a very hard time trying to figure out the equation for the coeficient of variation. I have looked at several statistics books along with our own class book. Could you please explain the equation." Hi, The coefficient of variation for any variable is just the standard dev., divided by the mean. In this case, we are using the sample standard deviation (in other problems it could also be the population standard dev.) The purpose of using CV is to measure how relatively variable two sets of data are. It avoids comparing "apples and oranges" which is what happens when comparing just the standard deviations alone. Note that the standard deviation is in units of measure such as inches, degrees or pounds, while CV is unit-free (it is a proportion) For instance, whose height varies more in our class, men or women? Because the average height for males is larger than for females, the standard deviation would probably tend to be also. (s measured in inches) But if we divided the std. dev. by the mean, we would have a fair comparison of variability. CV men = sm/qm bar CV women = sw /qw bar. MW ----- Original Message ----- From: "Brennain Garber" To: Sent: Friday, May 09, 2003 5:20 PM Subject: RE Coeficiant of variation > > Dear Professor, > I am having a very hard time trying to figure out the equation for the > coeficient of variation. I have looked at several statistics books along > with our own class book. Could you please explain the equation. > > Thank you for your time, > > Brennain Garber >