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A species with an initial population of 350

is growing in an environment where the
carrying capacity is 7000. After 5 years
the population is up to 900. Find the
logistic function that models this
population as a function of time.

User Gumenimeda
by
8.5k points

1 Answer

1 vote

Answer:

the logistic function that models the population of this species as a function of time is P(t) = 7000 / (1 + 0.05 * e^(-0.1682 * t)).

Explanation:

We can use the logistic growth equation to model the population of this species as a function of time:

P(t) = K / (1 + A * e^(-r * t))

Where:

P(t) is the population at time t

K is the carrying capacity of the environment

A is the initial population as a proportion of the carrying capacity (A = P(0)/K)

r is the growth rate of the population

We are given that the initial population A is 350/7000 = 0.05 (since the carrying capacity is 7000). We are also given that after 5 years the population has grown to 900. So we can use this information to find the growth rate r:

P(5) = 900 = K / (1 + A * e^(-r * 5))

We also know that the carrying capacity K is 7000. Substituting these values, we get:

900 = 7000 / (1 + 0.05 * e^(-r * 5))

Multiplying both sides by the denominator and simplifying, we get:

1 + 0.05 * e^(-r * 5) = 7.777...

Subtracting 1 from both sides, we get:

0.05 * e^(-r * 5) = 6.777...

Dividing both sides by 0.05, we get:

e^(-r * 5) = 135.555...

Taking the natural logarithm of both sides, we get:

-ln(135.555...) = -r * 5

Solving for r, we get:

r = 0.1682...

Now that we have the growth rate r, we can use the logistic growth equation to find the function that models the population as a function of time:

P(t) = 7000 / (1 + 0.05 * e^(-0.1682 * t))

Therefore, the logistic function that models the population of this species as a function of time is P(t) = 7000 / (1 + 0.05 * e^(-0.1682 * t)).

User Donnie Cameron
by
8.1k points