The Loudness of a Sound Can Be Approximated by the Formula

Multiple Choice

The loudness of a sound can be approximated by the formula $d=10 \log _{10} \frac{\mathrm{I}}{\mathrm{I}_{\mathrm{O}}}$ , where $\mathrm{d}$ is the number of decibels. The higher the value of $d$ , the louder the sound. Find the number of decibels when $\mathrm{I}=1000$ and $\mathrm{I}_{\mathrm{O}}=1$ .

A) 13 decibels
B) 30 decibels
C) 3 decibels
D) 1000 decibels