Problem $13-4($Algo$)$ Coefficient of variation $[$LO$13-1]$

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

$\backslash$table$[[,$Additional sales in$,],[$Possible Outcomes,Units,Prababilities$],[$Ineffective campaign,$70,0\mathrm{.}40],[$Normal response,$80,0\mathrm{.}20],[$Extremely effective,$140,0\mathrm{.}40]]$

Compute the coefficient of variation.

Note: Do not round intermediate calculations. Round your answer to $3$ decimal places.

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