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

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

$\backslash$table$[[,$Additional Sales,$],[$Possible outcomes,in Units,Probabilities$],[$Ineffective campaign,$30,0\mathrm{.}30],[$Normal$,$ response,$110,0\mathrm{.}50],[$Extremely effective,$130,0\mathrm{.}20]]$

Compute the coefficient of variation.

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

Coefficient of variation