Posted by jj on .
The decibel (dB) is defined as
dB= 10log (P2/P1), where P2 is the power of a particular signal. P1 is
the power of some reference signal. In the case of sounds, the reference signal is a sound level that
is just barely audible.How many dBs does a sound have if its power is 665,000 times that of the
reference sound? Round to the nearest tenth.
A) 134.1 dB
B) 58.2 dB
C) 25.3 dB
D) 10.0 dB
E) 0.0 dB

PreCalc 
Reiny,
dB = 10log(665 000) = 58.23