What scale factor is needed for a similarity transformation to transform a cube into a cube with twice the volume?

a = lenght of first cube

b = lenght of second cube

V1 = Volume of first cube

V2 = Volume of second cube

V1 = a^3

V2 = b^3

V1 / V2 = 2

a^3 / b^3 =2

a/b = third root of 2 = 1.25992