Math help? (Direct variations, Y= KX) ?

I've never been so confused in Math... I honestly mean that. The teacher explained it to me but I'm still confused. The directions say "The ordered pairs in each exercise are for the same direct variation. Find each missing value." One of the problems is, "(4,y) and (16, 12)" Can someone solve this for me and tell me what you did in every step? I'm so confused and math is usually easy for me.