posted by jR .
At 25 m from a sound source, the intensity level is 55 dB. What's the level at distance of 56m? What's the level at distance of 273m?
56 m is 2.24 times as far away as 25m, so the sound power/area is less by a factor of 2.24^2 = 5.02
The dB level is down by 10 log(10)5.02 = 7.0 dB