Al Bundy is evaluating a new advertising program that could increase shoe sales. Possible outcomes and probabilities of the outcomes are shown next.

Possible Outcomes Additional

Sales in Units Probabilities

Ineffective campaign $700\mathrm{.}20$

Normal response $1450\mathrm{.}20$

Extremely effective $3950\mathrm{.}60$

Compute the coefficient of variation. $($Do not round intermediate calculations. Round your answer to $3$ decimal places.$)$