1. The problem statement, all variables and given/known data Doing my own independent study, and I've come across a textbook question I'm rather lost on. Problem: Over the distance between two seismic recording sites at different ranges from a seismic source, seismic waves have been attenuated by 5dB. What is the ratio of the wave amplitudes observed at the two sites? 2. Relevant equations From what I can gather, the chapter offers: The ratio of two power values P1 and P2 is: 10log(P1/P2) dB Which also gives: 20log(A1/A2) (as power is proportional to the square of signal amp A) 3. The attempt at a solution This is where it all seems to go wrong with no real idea what direction I should be taking, this may be due to a lack of understanding somewhere. Given that the waves have decreased by 5dB between site A and B i went with: 20log(A1) = x (1) 20log(A2) = x - 5 (2) With A1 being the amplitude at site A and A2 being the amplitude at site B. This didn't seem to get me anywhere though as even after subbing 1 into two, i still have two unknown variables to find. Any help would be appreciated. I don't necessarily need a full answer but a little guidance as to whether I've understood the question wrong i.e. they're not asking for the amplitude at each site, or whether my method is completely off (or both).