Hello! Can someone please help me out for this question?

The loudness, L, of a sound in decibels can be calculated using the formula L= 10 log(I/ F) where I is the intensity of the sound in watts per square metre and F= 10^ -12 . A singer is performing to a crowd. Determine the intensity of the singers voice if the sound level is 90 dB.

This is what i have so far:

90 = 10 log [ I/F]
10^1.9543 = 10 log [I/F]

What should i do now?

* F is really a (I) with a zero underneath..but i didn't know how to type that in

1 answer

90 = 10 log [ I/F]

Use the properties of logarithms to isolate I.

9 = log(I/F)
10^9 = I/F