A sound's noise level is measured in decibels (dB) by comparing the sound's intensity, $I$, to a benchmark sound that has an intensity of $10^{-16}$ watts/cm$^2$. In particular,

a) The intensity of Joel's whisper is approximately $10^{-13}$ watts/cm$^{2}$. Compute the noise level of the whisper in decibels.
dB

b) A certain sound with a noise level of 96 dB has been known to damage hearing. Compute the sound's intensity at this noise level.
watts/cm$^2$

c) Kansas City Chiefs' fans recently broke the world record for "loudest roar" at a sports event. The fans reached a noise level of 142.2 dB. The previous world record was held by Seattle Seahawks' fans, with a noise level of 137.6 dB. About many times more intense was the roar of the Chiefs' fans than the roar of the Seahawks' fans?

Hint: