Find the variance and standard deviation of the following data : 4,6,10,12,14,18,20

Explanation

`because` Mean `barx=a+(Sigmad_i)/nxxh=12+0/7xx2`, where a =assumed mean
`therefore` Variance `sigma^2 =1/n Sigma(x_i-barx)^2=208/7=29.7`
and standard deviation =`sqrt29.7`=5.45