conditional sumproduct

I have engineer wise performance scorecard. I want to get manager wise scorecard taking every engineer from the team into account for the particular manager.
Manager name employee Name Sample Score (AVG)
A c 2 90%
A d 3 85%
A e 4 80%
A f 3 52%
A g 4 60%
B h 5 29%
B i 10 39%
B j 2 89%
B k 4 95%
B l 5 36%

How do I get overall score for Manager A and Manager B...basically manager score card derived from overall engineer scores....

what should be the formulae, I tried with sumproduct and sumproduct if together...However, I am not able to get the actual formula.