As given by the question
There are given 4.5 ounces of the mix for 6.5 ounces of water.
Now,
If 4.5 ounces of the mix for 6.5, then for the 1 ounces will be:
[tex]\begin{gathered} 4.5\rightarrow6.5 \\ 1\rightarrow\frac{6.5}{4.5} \\ 1\rightarrow1.44 \end{gathered}[/tex]Then,
For the 108 ounces of mix will be:
[tex]108\times1.44=155.52[/tex]Hence, 155.52 ounces of water would need to for 108 ounces of mix.