1. The problem statement, all variables and given/known data The problem was actually for a COMMS assignment that I have finished with the exception of the very last easiest part. They wanted percentage of power spilled into gaurd bands - have calculated all the powers now need the percentage.... I have two frequency components modulating the carrier and I have calculated power components. I end up with the following: f(Hz), P(W) - Channel 1 5, 1 10,5 15,2 20,3 25,4 f(Hz), P(W) - Channel 2 5, 1 15,5 20,2 25,3 30,4 Anything above 20kHz is spilled power and I want to know the percentage of spilled power (no thats no my actual results) The problem is that if I work out the percentages for channel 1 and 2 separately (& then sum) I end up with a higher percentage than if I just summed everything... What is the correct way to do this. ******Example may be easier to follow then my explanation***** Channel 1: Total power = 1+5+2+3+4W=15W Spilled Power (>20kHz)= 4W Percentage = 4/15*100=26.67% Channel 2: Total power = 1+5+2+3+4W=15W Spilled Power (>20kHz)= 3+4=7W Percentage = 4/15*100=46.667% CH1 + ch2 = 46.667+26.67=72% SPILLED Combined Total Power = 1+5+2+3+4+1+5+2+3+4=30W Spilled Power (>20kHz)= 4+3+4=11W Percentage = 11/30*100=37% SPILLED Why is there a discrepancy? I get mathematically why this is giving me two different results but which 1 would be the power spilled?