Question

The fish population of Lake Collins is decreasing at a rate of 5% per year. In 2000 there were about

1,150 fish. Write an exponential decay function to model this situation. Then find the population in
2006.

Answer 1

Number of fish in 2006 = 845 fishes (Approx.)

Explanation:

Given;

Number of fish in 2000 = 1,150 fishes

Decreasing rate = 5% per year

Find:

Number of fish in 2006

Computation:

Exponential decay function:

F = P[1-r]ⁿ

Number of year = 2006 - 2000

Number of year = 6 year

Number of fish in 2006 = 1,150[1-5%]⁶

Number of fish in 2006 = 1,150[1-0.05]⁶

Number of fish in 2006 = 1,150[0.95]⁶

Number of fish in 2006 = 1,150[0.735]

Number of fish in 2006 = 845.25

Number of fish in 2006 = 845 fishes (Approx.)