Question

By what factor must the sound intensity be increased to increase the sound intensity level by 13.0 dB ?

Answer 1

$SL=10lo{g}_{10}\left(\frac{I}{I_0}\right)$

or $13=10lo{g}_{10}\left(\frac{I}{I_0}\right)$

or $lo{g}_{10}\left(\frac{I}{I_0}\right)=1.3$

$\frac{I}{I_0}={10}^{1.3}=19.95\sim 20$