Time in hrs	Sound level (DBA)
5:00 - 7:00	43
7:00 - 9:00	56
9:00 - 11:00	64
11:00 - 13:00	70
13:00 - 15:00	69
15:00 - 17:00	55

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To determine the equivalent noise level, the following formula is used

dB = $20 \times log_{10} \times \frac{P}{P_{o}}$

For 43 dB :-

43 = $20 \times log_{10} \times \frac{P_{1}}{P_{o}}$

43 = $2 \times 10 \times log_{10} \times \frac{P_{1}}{P_{o}}$ = $10 \times log_{10} \times (\frac{P_1}{P_{o}})^2$

4.3 = $log_{10} \times (\frac{P_{1}}{P_{0}})^2$

$10^{4.3} …