Final answer:
An exponential decay model can be used to predict the percentage of light that reaches a certain depth in a clear lake. For a 19% light absorption per meter, the equation is P(d) = 100 * (0.81)^d. At a depth of 9 meters, approximately 14.1% of light remains.
Step-by-step explanation:
The intensity of light at a given depth in a clear lake can be modeled using an exponential decay function. In this case,
where we have a 19% absorption rate per meter, the function we'll use is of the form P(d) = 100 * (0.81)d, where P(d) is the percentage of light intensity at a depth d in meters, starting with 100% light at the surface.
Plugging the depth of 9 meters into the model to predict the percentage of light that will reach that depth, we get P(9) = 100 * (0.81)9 ≈ 14.1%.
Therefore, approximately 14.1% of the original light intensity will reach a depth of 9 meters in the lake.