SOLUTION: OK i need help with this question just on how to set it up- A man combines 7 fl oz of oil with 4 fl oz of vinegar. One day he needed a larger amount, so he used 8 fl oz of oil.

Question 242121: OK i need help with this question just on how to set it up-
A man combines 7 fl oz of oil with 4 fl oz of vinegar. One day he needed a larger amount, so he used 8 fl oz of oil. How much vinegar did he need?
please show me how to set it up into a proportion!!!
Found 2 solutions by checkley77, College Student:
Answer by checkley77(12844) (Show Source): You can put this solution on YOUR website!
7/4=8/x cross multiply.
7x=4*8
7x=32
x=32/7
x=4.57 oz. of vinegar are needed.
Answer by College Student(505) (Show Source): You can put this solution on YOUR website!
7 fluid ounces of oil is to 4 fluid ounces of vinegar as 8 fluid ounces of oil is to x fluid ounces of vinegar.
.
Thus the equation becomes:

.
You could also say:

.
Either one would yield the same answer. However, be very careful and mindful when creating your equation to place the same type of fluid in the numerators. You also need to ensure you use the same unit of measure (in this case the problem only dealt with fluid ounces, so it was easy), otherwise you'd need to convert the units of measure to obtain a correct result.
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