Coefficient of variation the coefficient of variation standardizes a variable's dispersion (standard deviation) relative to its mean. imagine two variables, each with a standard deviation of 20. if variable 1 has a mean of 100 and variable 2 has a mean of 10, it is obvious that more relative uncertainty. the coefficient of variation, the amount of risk per unit of the mean, is found by dividing the standard deviation by the mean, as follows: cv = standard deviation / mean check your understanding a vehicle's fuel efficiency is being tested. four trials yielded the following fuel efficiencies (in miles per gallon): 24.8 25.3 29.1 26.4 the mean fuel efficiency is 26.4 miles per gallon. the data from this fuel efficiency test represents a variance of these test results is the standard deviation is the coefficient of variation for the fuel efficiency results