Answer:
2.5
Explanation:
The relative volumes of the two similar boxes will be related by the cube of the dilation factor. That means the dilation factor (d) satisfies ...
1.2d³ = 18.75
d³ = 15.625 . . . . . divide by 1.2
d = 2.5 . . . . . . . . take the cube root
The scale factor the company needs to use is 2.5.