Question

The United States Census Bureau uses demographic information to set a poverty threshold that is used in to determine how many Americans are living in poverty based on annual income. For an individual on her own, the poverty threshold was $4,190 in 1980 and has increased by about $220 per year since then.
1. Which piece of information in the problem is a rate of change? What would that represent in a linear function modeling the poverty threshold?
2. When modeling information that changes with time, we almost never use the actual time--whether it's clock time or year--as input. Instead, we chose a beginning time for the problem and call that x=0. In this case, we would decide that x=0 corresponds to 1980 since that's the earliest time we have information for. In that case, what is the y-intercept for our function?
3. Write a linear function that describes the poverty threshold in dollars in terms of years after 1980. Then use your function to estimate the poverty threshold in 2010, and the year that it will pass $15,000 per year.
4. Use the Internet to find the most recent poverty threshold as set by the census bureau, and discuss how accurately your model predicted that value.

Answer 1

Answer:

Increment in property per year ;

Slope of a linear function

Kindly check explanation for the rest of the answers.

Step-by-step explanation:

The rate of change is the increment in property value per year ; $220

Thsi corresponds to the gradient or slope of a linear function

If 1980 = x and x = 0

Recall :

y = bx + c

Where, b = slope = 220

x = year

y = property threshold

c = intercept value

In 1980, x = 0

y - intercept.

Put x = 0 into the equation :

4190 = 220x + c

4190 = 220(0) + c

4190 = c

3.)

The linear function becomes :

y = 220x + 4190

Property threshold in 2010:

x = 2010 - 1980 = 30

y = 220(30) + 4190

y = 6600 + 4190

y = 10,790

Property threshold in 2010

Year it will exceed 15000

15000 = 220x + 4190

15000 - 4190 = 220x

10810 = 220x

x = 10810 / 220

x = 49.136

That is, property threshold will exceed 15000 after 50 years

1980 + 50 = 2030

Year 2030