5th grade
posted by colt .
I need an answer to the analogy
fifteen:five::nine: ?

fifteen divided by five is three.
To complete the analogy, divide nine by three. (Your answer is three) 
If the "analogy" is to preserve ratios on both sides, then the answer is 3. If the analogy is to preserve the difference, the answer is 1.
This is not a good way to teach fifth grade math, or analogies, in my opinion. The problem would be better stated as
15/5 = 9/x