Shack Homebuilders Limited is evaluating a new promotional campaign that could increase home sales. Possible outcomes and probabilities of the outcomes are shown next.

Possible Outcomes Additional Sales in Units Probabilities

Ineffective campaign 50 0.60

Normal response 90 0.20

Extremely effective 110 0.20

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