Need help to implement Business logic

Hey all,

      i am new to RoR and want to make a module FAIRPAY Facebook
application as following...

   * The user calculates their ranking
    * They compare their ranking with their friends
    * So if I have 100 friends who have used this Fair Pay FB app how
many get paid as industry standard, how many are not( for this i have
a algorthimn)
    * & where do I stand in the ranking of Effective Hourly Rate. So
if Jiten has 3 friends, Vishal, John, & Renu and their effective
hourly rates are:

Jiten = 8 Ranking (Jiten)=1
Vishal =2 Ranking (Vishal)=4
Renu = 3 Ranking (Renu)=3
John=5 Ranking (John)=2

Come up with a scoreboard displayed in FB that displays ONLY the
Ranking NOT the Effective hourly rate because Jiten, Vishal, Renu &
John don't know the other friends to find out their salaries.

Please help me how to implent this Business logic........
any suggestion will be highly appreciate.....
Thanks in advance...

Jitendra Sharma