Coef. of variation is the ratio, sigma/mean (or more precisely, est. sigma / average).
If the average drops below 0, the sign will change. Is this an issue? If not, forget it. If so, continue.... If the data sometimes falls below 0, then a sample will also fall below 0 occasionally. If this 'occasionally' is enough to consider, then ;you must recognize that occasionally the coef. of variation will go negative. Hence, we are back where we started, with a negative c of v. Does this help any? Jay Paul Smith wrote: > Dear All > > Some books say that the coefficient of variation can only be used if > the random variable is positive. I would like to know why cannot one > extend the use of the same coefficient with not necessarily positive > random variables but with positive mean. Could somebody here please > help me? > > Thank you a lot in advance! > > Paul > . > . > ================================================================= > Instructions for joining and leaving this list, remarks about the > problem of INAPPROPRIATE MESSAGES, and archives are available at: > . http://jse.stat.ncsu.edu/ . > ================================================================= -- Jay Warner Principal Scientist Warner Consulting, Inc. 4444 North Green Bay Road Racine, WI 53404-1216 USA Ph: (262) 634-9100 FAX: (262) 681-1133 email: [EMAIL PROTECTED] web: http://www.a2q.com The A2Q Method (tm) -- What do you want to improve today? . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
