Here's a little known but very useful factoid:
If they're inversely proportional,
then their product is constant.
Here's how to use it:
-- We're told that Y = 8 when X = 7.
So when y=8 and x=7, their product is 56 .
-- If Y REALLY varies inversely as X, then
their product is ALWAYS going to be 56.
-- So when Y=4, X= (56/4) = 14 .
