Help with what I *think* is a basic MDX calc

Hello,

I have what I think is an easy problem to tackle with MDX, but for the life of me I can't figure out how to do this and it's driving me crazy.

I have a cube with student-level data in it. Each student can have multiple Education records (one for each high school and/or college he/she went to), along with an Education Status for each record (i.e. "Currently Enrolled", "Graduated", "Dropped Out", "Withdrawn", "Transferred Out", etc.).

I need to create a "Graduation Rate" MDX Calculated Measure that takes the number of students that have Graduated (Status = Graduated") and divides that by the number of Students that DID NOT "Transfer Out".

So: Number of Students Graduated / Number of students Enrolled, Graduated, Dropped Out, Withdrawn, etc (this needs to be a distinct count, so if a student has all three statuses, he only counts once in this calculation).

I can get the numerator in this equation, but for the life of me I cannot find a way to get the denominator in this equation. Please help!

Jon