How total/average is calculated?

[kardashian]

How is total/average calculated?
For example: Column/Stat 'PFR' in 'Position' report and the number that is at the bottom row (row with totals/averages).

I tried to sum 'PFR' for each position and calculate average, but result differs from the number in HEM.
My guess is that I need total Opportunities and total PFR Actions to calculate this (Total_PFR / Total_Opportunities).
If so, any tips?

Thanks!

[fozzy71]

Correct, the totals row for stats is a 'Total Weighted Average' of each row above it. The number of opportunities for a stat in each row above can vary drastically based on the number of hands in each row.