The coefficient of variation of a dataset is given by the ratio between the standard deviation to the mean.
[tex]CV=\frac{\sigma}{\mu}[/tex]The mean and the standard deviation of a dataset with N elements are given by the following formulas:
[tex]\begin{gathered} \mu=\frac{\sum_i^Nx_i}{N} \\ \\ \sigma=\sqrt{\frac{1}{N-1}\sum_{n\mathop{=}0}^{\infty}(x_i-\mu)^2} \end{gathered}[/tex]Then, using those formula for the security service company, we have the following coefficient of variation:
[tex]\begin{gathered} \mu=1.53 \\ \sigma=0.15670212364724... \\ CV=0.102419689...\approx10.2\% \end{gathered}[/tex]Then, using those formula for the other companies, we have the following coefficient of variation:
[tex]\begin{gathered} \mu=1.72 \\ \sigma=0.11352924243951... \\ CV=0.0660053735...\approx6.6\% \end{gathered}[/tex]