Specific criteria to get mximum result

[Alex G]

I would like help with what I call an optimised result from an average formula.
Can an average result be multiplied automatically to return an optimised number?
So for example, if the straight average of the b column in c5 was multiplied by 3.9 it would return an optimised number (B4) which can then be fed into a2's formula. The aim of this would be to produce the highest figure possible in the a2 cell from the data in A & B. Can c5 'look' at a2 then multiply itself to return the highest figure for a2 ?

Thanks in advance.

Alex G