<PRE><B>Question 1202993</B>
Start with a proportion and you will have just one unknown quantity to solve.


The given ratio is  {{{4/1}}} {{{ounce_concentrate/gallon_water}}}.


The asked for 1 CUP of water can be handled like so, if you want:
1 gallon is 128 fluid ounces.
8 fluid ounces is 1 cup.
-
{{{1*cup*8(fluidounces/cup)*(1/128)*(gallon/fluidounces)}}}-------{{{8/128}}}{{{gallons}}}
0.0625 gallons of water.


Then you could set up a proportion as  {{{4/1=w/0.0625}}}
and solve for w.


---------------------------------A BETTER WAY--------------------------------------

Recognize or easily find that 1 gallon is 16 cups.

The question description can then be: 
the bottle says to add 4 oz of concentrate to 16 cups of water but i only need to make mixture with 1 cup of water, how much concentrate should i mix with 1 cup of water?


Now you can set up a proportion as  {{{4/16=Q/1}}}.
This means, that Q is  {{{1/4}}} cups.</PRE>