The problem states: A microphone in the ocean is sensitive to sounds emitted by popoises. To produce a usable signal , sound waves striking the microphone must have an intesity of 10.6 dB. If porpoises emit sound waves with a power of 0.0502 W, how far can a porpoise be from the microphone and still be heard? Disregard ansorbtion of sound waves by water. I tried putting 10.6 decibels in the equation dB=10Log(I/Io) and I solved for intensity to be 1.148E-10W/m^2 I then used that number in the I = P/4pi r^2 formula. Solving for r I got 5.89E+3m. But the right answer it the book is 1.87E+4 Can anyone tell me where I went wrong??