Answer:
93 dB
Explanation:
[tex]dB \rightarrow \textrm{sound level}\\ I \rightarrow \textrm{sound intensity}\\ I_0 \rightarrow \textrm{threshold sound intensity}\\ x \rightarrow \textrm{distance of corresponding to threshold intensity of hearing}[/tex]
[tex]80.2\;\rm dB = 10\; log_{10}\;\left(\dfrac{I}{I_0} \right)\\ \dfrac{I}{10^{-12}} = 10^{8.02}\\ I = 0.000104713\;\rm W/m^2\\ \boxed{I \approx 0.000104713\;\rm W/m^2}[/tex]
For 19 such singers then intensity will be
[tex]I_19=19I= 19\times 0.000104713=0.001989544[/tex]
The intensity in dB will be
[tex]I_{19}(dB)=10log\frac {0.001989544}{10^{-12}}=92.98753601\approx 93 dB[/tex]
