Please explain thoroughly Thanks The loudness L in decibels

Please explain thoroughly. Thanks.

The loudness, L : in decibels(dB), is given by the formula L = 10 middot log 1/I_0, where I_0 = 10^-12 W/m^2. The intensity, L of a sound is 3.3 Times 10^ -6 W/m^2. How loud in decibels is this sound level?

Solution

L = 10. log (I/I₀)

Given I = 3.3 X 10^-6 W/m²
   I₀ = 10^-12 W/m²

Substituting the value of I and I₀ in the above equation, we get
L = 10. log ( 3.3X10^-6 / 10^-12)

L = 10. log (3.3X10⁶)

L = 10 X 6.52 = 65.2 db