Question

noise in a quiet room is 500 times for as intense as the threshold of sound. what is the decibel measurement for the quiet room?

Answer 1

For this case, the first thing you should do is observe the graph.
 We have that the x-axis represents the intensity of the sound.
 The y-axis represents the measure in decibels.
 We have then:
 For x = 500 the value of y is y = 28
 Answer:
 The decibel measurement for the quiet room is:
 28 decibels