Answer:
11.45 lumens
Step-by-step explanation:
We are given that
[tex]log(I/12)=-0.00235x[/tex]
Where x=Depth
I=Intensity of light
We have to find the intensity of the light at a depth of 20 feet.
Substitute the value of x
[tex]log(I/12)=-0.00235\times 20[/tex]
[tex]log(I/12)=-0.047[/tex]
[tex]\frac{I}{12}=e^{-0.047}[/tex]
[tex]I=12e^{-0.047}[/tex]
[tex]I=11.45 Lumens[/tex]
Hence, the intensity of the light (in lumens) at a depth of 20 feet=11.45 lumens