Server issues.
 

I have Lampp running on my machine perfectly fine.
However, I asked a girl from around my home (off my college campus) who would be out of my campus network obviously to view my website.

http://ip-181-157.emich.edu

she informed me it doesn't work. However every computer on campus seems to render it as long as my server is online.

Is this because I need a domain name? Or what could be a problem?

The university probably runs an application gateway which filters out port 80 for all IP's but the one for it's own site. Just a guess. However, the link you supplied does resolve to an address. There is no response for http however.