It is very critical! Much obliged! Ill see what i can pull off without passing out!
Any Native German Speakers?

maybe it is better to keep it in english maybe she replies in german something you do not understand.
imagine the akward moment if you have to ask if that means yes or no.

Begleitest Du mich zum Ball?
Easy question. I hope, she will answer yes :-)
Elegant, yet simple. Best answer so far.

True, but a little too formal, isn't it? I couldn't imagine a 17-year-old German actually saying this - that is, in our days, not in a 1950's black-and-white movie or unless he is really far on the nerdy side.
How would you translate 'prom' then?
Also remember, he needs to pronounce it correctly too, so anything too complicated won't do good either.
Begleitest Du mich zum Ball?
Easy question. I hope, she will answer yes :-)
i agree best version, definetly not formal
True, but a little too formal, isn't it? I couldn't imagine a 17-year-old German actually saying this - that is, in our days, not in a 1950's black-and-white movie or unless he is really far on the nerdy side.
nah i dont think so

I like: "Willst du mit mir zum Prom gehen". Why? It's basically English, easy to understand for an English speaker (Will you with me to Prom go?). Prom must not be translated, as it is a proper, specific name, unless there is something equal to it in Germany, perhaps "Collegeball".
How would you know? You are Japanese, right?
The Tenno likes germany, after all they were allies.

How would you know? You are Japanese, right?
The Tenno likes germany, after all they were allies.
Weeeell, I have to admit .... I like you too, Japan!
The only Japanese I know is:
uma - horse
neko - cat
ramen - noodle soup
I'm sure I could recall some more, given the time ...

Well, 'prom' can only roughly be translated - if at all - because we don't actually have something like this in Germany anymore, or at least it doesn't have the same importance and meaning as it has in the USA. (Or maybe there's a neocon rollback that I've missed and these things are coming back.)
When I finished school, there was an official party, but it was dull beyond description, we only stayed there for as long as to meet the minimum formal requirements and then we got drunk elsewhere, IIRC we even ended up on some teacher's balcony. That's not what I'm thinking about when I read the term "prom".
Abiball. The word you're looking for is Abiball.
But they don't have "Abitur" in America, so why not just 'Ball'?
Some things really can't be toned down in formality, like an invitation for a High School prom e.g., otherwise it just sounds needlessly vulgar.
"Hey Alte, haste Bock uff Tanzen?"

Give Norwegian a try will you?? The ugliest language on earth:P I prefer: Begleitest Du mich zum ball. Elegant and sofisticated, stylish I would say. But, what do I know?? Beeing a Norwegian:P I had six years with German at school:)
Interesting question. Back about 100 years or so to when Kaiser Bill was still in charge over there one might have asked: " Darf ich Sie zu dem Prom begleiten ? " ( using the more formal " Sie " ). However in these more modern Post-Adenauer times: " Willst Du mit mir zum Prom gehen ? " is a more informal way to ask the young lady ( as per the 1st suggestion in this thread ). The OP did not mention how well he knows this girl, she is in the same Grade perhaps ?
Hey,
I plan on asking a girl at my school to prom who speaks German - I plan to attempt and ask her in German! But Google Translate is no good, and I feel worried by my attempt at Translation:
Willst du mit mir zum Prom gehen?
Any help would be appreciated!
Thanks