Question

A population of 30,000 fish is expected to shrink at a rate of 7.5% per year.

Which is the best prediction for the fish population in 8 years?

Answer 1

30,000(1−7.5/100)8≈16078.9

Answer 2

Answer: 16079

Explanation:

The exponential decay function for population after x years is given by :-

`f(x)=A(1-r)^x`, where 'A' is the initial population , 'r' is the rate of decay per year and 'x' is the number of years.

Given: The initial population of fish = 30,000

The rate of decrease in the population of fish per year = 7.5%=0.075

Now, the population of fish after 8 years is given by :-

`f(8)=30000(1-0.075)^8=30000(0.925)^8=16078.8549221\approx\ 16079`

Hence, the best prediction for the fish population in 8 years =16079