Advanced(!) Ranking

[Marie Bayes]

Hi
I need to enter a ranking, but am really struggling, I've been given some
great formulae using sumproduct, but, being no expert I'm not sure quite how
to use this for what I want, which is:

I have x columns of data, Region Manager, Area Manager, Sales person,
Average Score for Area Manager (based on a score for each sales person)
I need a column to represent the ranking of the Average Score within its
area.

The resulting column should look something like RANK below - so, does anyone
have any idea what this formula may be - Thanks in advance

RM AM SP Score Average
Score RANK
AR1 AM1 SP1 1 1.5 3
AR1 AM1 SP2 2 1.5 3
AR1 AM2 SP3 3 3.5 2
AR1 AM2 SP4 4 3.5 2
AR1 AM3 SP5 5 6 1
AR1 AM3 SP6 6 6 1
AR1 AM3 SP7 7 6 1
AR2 AM4 SP8 8 9.25 2
AR2 AM4 SP9 9 9.25 2
AR2 AM4 SP10 10 9.25 2
AR2 AM4 SP11 11 9.25 2
AR2 AM5 SP12 12 13 1
AR2 AM5 SP13 13 13 1
AR2 AM5 SP14 14 13 1
AR2 AM6 SP15 1 1 3
AR2 AM6 SP16 1 1 3
AR2 AM6 SP17 1 1 3

 

[Marie Bayes]

Just to clarify as my table below is not 100% accurate(!), the highest
average score should be ranked first.