The group having higher coefficient of variation will be more variable

So, we will calculate

Where σ is standard deviation

is mean

For group A

Mean

Where A is assumed mean = 45

h = class size= 20- 10 = 10

Mean,

Variance

=

=

Standard deviation =

C.V._A=

For group B

Variance

=

=

Standard deviation =

Since the coefficient of variance of group B coefficient of Group A

∴ Group B is more variable