Question

The following table gives projections of the population of a country from 2000 to 2100.
Answer parts ​(a) through ​(c).
Year
Population​ (millions)
Year
Population​ (millions)

2000
281.6
2060
437.8
2010
306.8
2070
470.8
2020
330.8
2080
502.8
2030
357.3
2090
541.8
2040
386.5
2100
574.9
2050
411.8
Question content area bottom
Part 1
​(a) Find a linear function that models the​ data, with x equal to the number of years after 2000 and​ f(x) equal to the population in millions.
​f(x)equals
  
enter your response herexplus
  
enter your response here
​(Type integers or decimals rounded to three decimal places as​ needed.)
Part 2
​(b) Find ​f(75​). State what the value of ​f(75​) means.
​f(75​)equals
  
enter your response here ​(Round to one decimal place as​ needed.)
Part 3
State what the value of ​f(75​) means.
A.
The projected population is
  
enter your response here million in the year 2175.
B.
The projected population is
  
enter your response here million in the year 2075.
Part 4
​(c) What does this model predict the population to be in​ 2080? How does this compare with the value for 2080 in the​ table?
The population in the year 2080 will be
  
enter your response here million.
​(Round to one decimal place as​ needed.)
Part 5
How does this compare with the value for 2080 in the​ table?

Answers

GPT-4o mini
To answer your questions, we need to find a linear function that models the population data given, and then evaluate it based on the required parts.

### Part 1: Finding the linear function

We will create a linear function \( f(x) = mx + b \), where \( x \) is the number of years after 2000, and \( f(x) \) is the population in millions.

First, we extract the data points from the table:

- (0, 281.6)
- (60, 437.8)
- (100, 574.9)

To find the slope \( m \):

\[
m = \frac{f(100) - f(0)}{100 - 0} = \frac{574.9 - 281.6}{100 - 0} = \frac{293.3}{100} = 2.933
\]

Now, using the point-slope form for one of the points (let's use (0, 281.6)):
- \( b \) is the population at the year 2000, which is 281.6 million.

Thus, the linear equation is:

\[
f(x) = 2.933x + 281.6
\]

So the linear function \( f(x) \) is:

1. **a)** \( f(x) = 2.933x + 281.6 \)

### Part 2: Finding \( f(75) \)

Now we substitute \( x = 75 \):

\[
f(75) = 2.933(75) + 281.6
\]

Calculating this:

\[
f(75) = 219.975 + 281.6 = 501.575
\]

Rounding to one decimal place gives us:

2. **b)** \( f(75) = 501.6 \)

### Part 3: Interpretation of \( f(75) \)

- \( f(75) \) corresponds to the year \( 2000 + 75 = 2075 \).

So the correct interpretation is:

3. **Answer:** B. The projected population is 501.6 million in the year 2075.

### Part 4: Predicting the population in 2080

Next, we predict \( f(80) \) (2080 corresponds to \( x = 80 \)):

\[
f(80) = 2.933(80) + 281.6
\]

Calculating this:

\[
f(80) = 234.64 + 281.6 = 516.24
\]

Rounding to one decimal place gives:

4. **Answer:** The population in the year 2080 will be **516.2 million**.

### Part 5: Comparison with the table

The table shows that the population in 2080 is 502.8 million. Our model predicts:

- \( 516.2 \) million (model prediction)
- \( 502.8 \) million (from the table)

5. **Comparison:** The model prediction of 516.2 million is higher than the table value of 502.8 million.

### Summary of Answers
1. **(a)** \( f(x) = 2.933x + 281.6 \)
2. **(b)** \( f(75) = 501.6 \)
3. **(c)** B. The projected population is 501.6 million in the year 2075.
4. **(d)** The population in the year 2080 will be 516.2 million.
5. **(e)** The model prediction is higher (516.2 million) than the table value (502.8 million).