The population of a community is known to increase at a rate proportional to the number of people present at time t. The initial population P0 has doubled in 5 years. Suppose it is known that the population is 9,000 after 3 years. What was the initial population P0? (Round your answer to one decimal place.) P0 = What will be the population in 10 years? (Round your answer to the nearest person.) persons How fast is the population growing at t = 10? (Round your answer to the nearest person.) persons/year

Respuesta :

Answer:

Part 1) [tex]p_0=5,937.8\ people[/tex]

Part 2) [tex]23,752\ people[/tex]

Part 3) [tex]1,781\ persons/year[/tex]

Step-by-step explanation:

In this problem we have a exponential growth function of the form

[tex]p(t)=p_0(1+r)^t[/tex]

where

p_0 is the initial population

t is the number of years

r is the rate of change

we have that

The initial population p_0 has doubled in 5 years

so

[tex]p(5)=2p_0[/tex]

substitute in the equation above

[tex]2p_0=p_0(1+r)^5[/tex]

solve for r

[tex]2=(1+r)^5[/tex]

elevated both sides to 1/5

[tex]r=2^{\frac{1}{5}} -1[/tex]

[tex]r=0.1487[/tex]

substitute

[tex]p(t)=p_0(1+0.1487)^t[/tex]

[tex]p(t)=p_0(1.1487)^t[/tex]

Find the value of p_0

Remember that

the population is 9,000 after 3 years

so

substitute

[tex]9,000=p_0(1.1487)^3[/tex]

[tex]p_0=5,937.8\ people[/tex]

so    

[tex]p(t)=5,937.8(1.1487)^t[/tex]

What will be the population in 10 years?

For t=10 years

substitute

[tex]p(t)=5,937.8(1.1487)^{10}= 23,752\ people[/tex]

How fast is the population growing at t = 10?

we know that

For t=0 ----> P=5,937.8 people

For t=10 ---> P=23,752 people

so

[tex](23,752-5,937.8)/(10-0)=1,781\ persons/year[/tex]

The question is an illustration of an exponential function

  1. The initial population is 5921
  2. The population is growing at a rate of 2395 persons per year when t =10

An exponential function is represented as:

[tex]P = P_o * r^t[/tex]

The initial population doubled in 5 years.

So, we have:

[tex]2P_o = P_o * r^5[/tex]

Divide both sides by Po

[tex]2 = r^5[/tex]

Take the 5th roots of both sides

[tex]r = 1.15[/tex]

So, we have:

[tex]P = P_o * 1.15^t[/tex]

The population in 3 years is 9000.

So, we have:

[tex]9000 = P_o * 1.15^3[/tex]

[tex]9000 = P_o * 1.52[/tex]

Divide both sides by 1.52

[tex]P_o =5921[/tex]

So, the initial population is 5921

When t = 10, we have:

[tex]P = P_o * 1.15^t[/tex]

[tex]P = 5921 * 1.15^{10[/tex]

[tex]P = 23954[/tex]

The rate is then calculated as:

[tex]r = \frac{P}{10}[/tex]

[tex]r = \frac{23954}{10}[/tex]

[tex]r = 2395[/tex]

Hence, the population is growing at a rate of 2395 persons per year

Read more about exponential functions at:

https://brainly.com/question/11464095