Question

The population of fish in an aquarium can be modeled after exponential growth. If there were originally 3 fish and after 6 weeks there were 31 fish, how many fish would there be after 14 weeks?​

Answer 1

The population in 14 weeks is 232 fishes

Explanation:

The equation for exponential growth is f(x) = a·(1 + r)ˣ

Where;

a = The starting population size = 3

r = The rate at which the population of grows

x = The number of periods to of change of the population

Therefore, we have;

f(6) = 31 = 3 × (1 + r)⁶

31/3 = (1 + r)⁶

㏑(31/3) = 6㏑(1 + r)

(㏑(31/3))/6 =㏑(1 + r)

1 + r = e^((㏑(31/3))/6) ≈ 1.476

1 + r ≈ 1.476

Therefore, the population in 14 weeks is given as follows;

f(14) = 3 × (1.467)¹⁴ ≈ 232.574

Given that we the information is with regard of living things, such that there are no fractions, we round down to the nearest whole number as follows;

f(14) ≈ 232

The population in 14 weeks = 232 fishes.