Math Problem Statement

The logistic growth model Upper P left parenthesis t right parenthesis equals StartFraction 1000 Over 1 plus 30.42 e Superscript negative 0.449 t EndFraction represents the population​ (in grams) of a bacterium after t hours. Answer parts​ (a) throught​ (f). Question content area bottom Part 1 ​(a) Determine the carrying capacity of the environment. The carrying capacity of the environment is    1000 g. Part 2 ​(b) What is the growth rate of the​ bacteria? The growth rate is    44.9​% per hour. ​(Type an integer or a​ decimal.) Part 3 ​(c) Use a graphing utility to graph Upper P equals Upper P left parenthesis t right parenthesis. The graphs are shown in the viewing window Upper X Subscript minequals​0, Upper X Subscript maxequals​20, Upper X Subscript sclequals​2, Upper Y Subscript minequals​0, Upper Y Subscript maxequals1000​, Upper Y Subscript sclequals200. Choose the correct graph below. A.

x y graph B.

x y graph C.

x y graph D.

x y graph Your answer is correct. Part 4 ​(d) What is the population after 5 ​hours? After 5 ​hours, the population is    enter your response here g. ​(Do not round until the final answer. Then round to the nearest tenth as​ needed.)

Solution

Let's address each part of the problem one by one:

Part 1: Carrying Capacity

The carrying capacity is already identified as 1000 grams, which is the maximum value of P(t)P(t) when tt \to \infty.


Part 2: Growth Rate

The growth rate is given as r=0.449r = 0.449, which translates to 44.9% per hour.


Part 3: Graphing the Model

The graph represents logistic growth, starting at a low population, increasing rapidly during the growth phase, and leveling off near the carrying capacity (1000 grams). You can plot the function in the specified range: P(t)=10001+30.42e0.449tP(t) = \frac{1000}{1 + 30.42e^{-0.449t}} Given Xmin=0,Xmax=20,Ymin=0,Ymax=1000X_{\text{min}} = 0, X_{\text{max}} = 20, Y_{\text{min}} = 0, Y_{\text{max}} = 1000, the curve should match the description provided.


Part 4: Population After 5 Hours

The population at t=5t = 5 is calculated using the given logistic growth model: P(5)=10001+30.42e0.4495P(5) = \frac{1000}{1 + 30.42e^{-0.449 \cdot 5}}

  1. Compute e0.4495e^{-0.449 \cdot 5}: 0.4495=2.245,e2.2450.106-0.449 \cdot 5 = -2.245, \quad e^{-2.245} \approx 0.106

  2. Calculate the denominator: 1+30.420.1061+3.224=4.2241 + 30.42 \cdot 0.106 \approx 1 + 3.224 = 4.224

  3. Find P(5)P(5): P(5)=10004.224236.8gramsP(5) = \frac{1000}{4.224} \approx 236.8 \, \text{grams}

Thus, the population after 5 hours is approximately 236.8 grams.


Part 5: Additional Questions to Expand Understanding

  1. How does the logistic growth model differ from exponential growth in long-term population prediction?
  2. What happens to the rate of growth as tt \to \infty in this logistic model?
  3. Can the growth rate of 44.9% per hour remain consistent indefinitely in the real world? Why or why not?
  4. How sensitive is the population prediction to changes in the initial population size (e.g., P(0)P(0))?
  5. What does the parameter 30.4230.42 represent in the context of the logistic model?

Tip: In logistic growth, the population grows rapidly initially but slows down as it approaches the carrying capacity due to limited resources. This is a key difference from exponential growth.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Logistic Growth
Exponential Functions
Population Dynamics

Formulas

Logistic growth model: P(t) = K / (1 + Ae^(-rt))
Exponential decay: e^(-rt)

Theorems

Logistic Growth Theorem
Limits of Exponential Functions

Suitable Grade Level

Grades 11-12