First and foremost I'm no mathematician, it may be a case of over complication.
What I'm trying to do is that I have 2 sets of data, I want to calculate one average for both sets but I want the first set to have more 'influence' over the average than the second.
I.e I want an outlier in set A to swing the average more than if that outlier was in set B (If that makes any sense).
I would assume I'd need a value to deem how much of an effect each set would have.
I don't expect a specific answer but if someone could get me started/point me in the right direction I'd be grateful.