Folding AK for your stack?

[nlsnakeyes520]

I am playing a $55 dollar multi tourny. 130 players left and the average chip stack is about 3700--I have 4165 in chips. I have just been moved to this table about 4 hands ago and witnessed nothing at the table thus far, so no reads. I pick up AK in the SB 75/150 blinds. A small stack goes all in for his last 500 chips then two players later a large stack moves all his 7000 chips in with 4 players still to act behind him, two large stacks, myself and another small stack. What should I do, what should I put him on?