The intensity of the sound from a certain source is measured at two points along a line from the source. The points are separated by 13.9 m, the sound level is 76.80 dB at the first point and 66.72 dB at the second point.
a) How far is the source from the first point?
(Assume an inverse square law, i.e., the intensity falls off as 1/r^2)
b) Calculate the power output of the source