I'm fairly new and i was wondering if joining a party gives bonus exp per kill.

No, it gives less xp per kill, but you will be able to attract much more mobs in a full pt than solo. Overall, partying xp is much, much better than solo.

i kinda of meant, total exp per kill. like...i know each person would get more if they killed it themselves, but what about total combined exp per kill across each person?

example:

solo u get 1000 exp per mob. in 4 ppl party u wont get 250xp, u would get like 300+ i guess. dunno how exactly it's calculated, but yes, u get more than solo exp / party members

ah ok. that's exactly the answer i needed =)