Answer
y=2.6x; 31.2
Work Step by Step
We know direct variation has the equation y=kx. Thus, we plug in the points and solve for k:
$ y=kx \\\\ 10.4=4k \\\\ k=2.6$
We substitute k back in to get the equation: $y=2.6x$
We now plug in x=12:
$y=(2.6)(12)=31.2$