Answer:
1.58 W
Explanation:
Since the sound spreads uniformly in all directions, it must be in a form of a circle with radius of 12 m. So the area of the circle is
[tex]A = \pi r^2 = \pi 12^2 = 452.389 m^2[/tex]
From the intensity of the sound we can calculate the power at 12 m
[tex]P = AI = 452.389 * 3.5\times10^{-3} = 1.58 W[/tex]