Answer:
4/9
Explanation:
The scale factor for the linear dimensions of the ball bearings will be the cube root of the volume scale factor:
k = ∛(1.6/5.4) = 2/3
Then the scale factor for the areas will be the square of this scale factor:
ratio of surface area = (2/3)² = 4/9
_____
The area is the product of two linear dimensions, so its scale factor is the product of the linear dimension scale factors. That is, the scale factor for area is the square of the linear dimension scale factor.
Similarly, volume is the product of three linear dimensions, so its scale factor is the cube of the linear dimension scale factor.