Square A has side lengths each measuring x inches. Square B has side lengths each measuring 2x inches. What is the ratio of the area of the smaller square to the area of the larger square? Express your answer as a common fraction.
Area of smaller square = x^2
Area of larger square= (2x)^2 = 4x^2
Ratio of areas = x^2 / 4 x^2 = 1 / 4