The sum of the squares deviations for 10 observations taken from their mean 50 is 250. The coefficient of variation is
10%
40%
50%
none of these
Let x1,x2,…,x10 be 10 observations. Then,
∑i=110 xi−502=250
∴ σ2=110∑i=110 xi−502=25010=25⇒σ=5
∴ Coefficient of variation =σX¯×100=550×100=10%