Hey there! Thanks for asking your question here on Brainly!
For this sort of problem, we'll use the equation y = k/x, which is for inverse variations. First, we'll need to solve for k.
4 = k/12
k = 48
Next, we'll need to plug k into our equation from the beginning, as well as 3 for x in order to solve for y.
y = 48/x
y = 48/3
y = 16
Therefore, your answer is y = 16.
Hope this helps!! :)