Question 1036076
The relationship looks like this:

{{{y = k*sqrt(z)/x^3}}}
Now we plug in the original facts to find k...
{{{3 = k*sqrt(4)/2^3}}}
and we find
k = 12
Now we rewrite our relationship with the new k and plug in 2nd set of facts...
{{{y = 12*sqrt(z)/x^3 = 12*sqrt(16)/4^3 = 48/64 = 3/4}}}