[Masonite]

As per dictionary.com:
Minority
1. the smaller part or number; a number, part, or amount forming less than half of the whole.
2. a smaller party or group opposed to a majority, as in voting or other action.
3. a group differing, esp. in race, religion, or ethnic background, from the majority of a population: legislation aimed at providing equal rights for minorities.
4. a member of such a group.
5. the state or period of being under the legal age of full responsibility

Referring mainly to the "majority of A population", notice it does not say "THE population", so with you stating that you are a minority in the population of your school, you are 100% right on.
The buzzkill, though, is that (and I may be wrong about this) most applications refer to a minority as someone in a smaller racial group in relation to its country.

Personally, I just leave the race and religion parts blank. I don't want to be seen as "oh, just another white guy" in a stack of papers before reading into my resumé.