It is 3 1/8 because 9.2 is a decimal and a fraction is 3 1/8 and a mixed fraction is 3 7/8
We are tasked to solve for the ratio of the two boxes. Boxes are cubes. We can use the formula in solving the surface area of the box as shown below:
Surface Area of Cube = 6a² where "a" is the length of the side.
For smaller box:
Area= 6(12)²=864
Area =864
For the larger box:
Area = 6(18)²
Area=1944
Then, the ratio is:
Area smaller box/Area larger box =864/1944
Ratio=4:9
I am not sure on how to do this however here is a link with information thst will be able to help you around this subject.i hope this helps
https://www.bbc.com/bitesize/guides/z8k887h/revision/1