What approximate change in decibles does an observer experience form a sound source if the oberver moves to a new location that is 67% as far from the source?

23
-23
40
2.76
-2.76
1.94
-1.94
2.57
-2.57
0

3 answers

do I multiply .67 times 10 log .67?
There will be (1/0.67)^2 = 2.23 times more sound intensity (power) per area at the closer distance

10 x log(10)2.23 = 3.5 dB more

I do not agree with any of the choices.
those are the answer choices in my book...