Weighted Means in Zoho Reports?

Weighted Means in Zoho Reports?

I need to display a weighted mean in a chart report that recalculates when user filters change.  There is a formal definition of the weighted mean at http://en.wikipedia.org/wiki/Weighted_mean#Mathematical_definition.  But here is an example:

Category      Value      Frequency
California      25      100
Arizona      35      50
Nevada      10      25

The weighted mean of the unfiltered data would be (2500 + 1750 + 250) / (100 + 50 + 25) = 25.71.  The arithmetic mean would be (25 + 35 + 10) / 3 = 23.33. 

Is there any way to get this in a Zoho Reports chart?

Thanks,
Jon