Step 1:

(a)

The level of sound is  .

Standard intensity of sound is .

Intensity of sound of quiet room is .

Power property of logarithms: .

The level of Sound is .

Solution:

The level of Sound is .

Step 1:

(b)

The level of sound is  .

Standard intensity of sound is .

Intensity of sound of busy street corner is .

Power property of logarithms: .

The level of Sound is .

Solution:

The level of Sound is .

Step 1:

(c)

The level of sound is  .

Standard intensity of sound is .

Intensity of sound of quiet radio is .

Power property of logarithms: .

The level of Sound is .

Solution:

The level of Sound is .

Step 1:

(d)

The level of sound is  .

Standard intensity of sound is .

Intensity of sound of threshold of pain is .

Power property of logarithms: .

The level of Sound is .

Solution:

The level of Sound is .