While the average call time was close (4.5 minutes vs. 4.3) one team had a standard deviation of 1.5 minutes, while the other was 2.75 minutes, respectively. This resulted in a CoV of 33.33% vs. 64%.

The COV is equal to the ratio between the standard deviation and the mean. Although COV is most commonly used in comparing relative risk, it may be applied to many types of probability distribution.