He has one of two things: (1) a hand that crushes you, or (2) crap, and he thinks you raised PF with 78s or something and he's trying to look you up. I really don't understand #2 but I make a good bit of money from it. I also probably fold too often because of it, too.
For the odds, ... dunno. I posted a
somewhat similar hand where I was getting even better odds to call even tho the river brought a scary card.
Saying "that's weak-tight" only marginally helps. Yeah, great, I play too weak-tight. What does he have? How often? Was a mistake made earlier in the hand that would have prevented his behavior?