[330d xdrive Scotty]

Had the car into BMW today for its MOT and it has failed on front brake imbalance by 27%

My question is there a way to manually verify the imbalance from the recorded readings on the results sheet ?

My LH brake force was 278 kgf and the RH 301 kgf and the computer has determined this is 27% out ?

I found some info on the net about working it out with the formula:
(Highest - lowest) / highest * 100 = Imbalance %

Is it as simple as this, because it works out as 7.64%

My BMW garage dont want to know stating 'The computer works it out and it says your car is a fail'

Any help greatly appreciated !!