The table shows the national expenditures for health care​ (in billions of​ dollars) for selected years from 2002 and projected to 2024.​ (These data include expenditures for medical research and medical facilities​ construction.)

Complete parts ​(a) through ​(c) below.
Year
Expenditures
Year
Expenditures

2002
1602
2014
3080
2004
1856
2016
3403
2006
2113
2018
3786
2008
2414
2020
4274
2010
2605
2022
4825
2012
2817
2024
5425
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 y equal to the expenditures for health care in billions of dollars. Report the model with 3 significant digits.

yequals
  
enter your response herexplus
  
enter your response here
Part 2
b. What does the reported model predict the expenditures will be in 2050​?
​$
  
enter your response here billion ​(Use the answer from a to find this​ answer.)
Part 3
c. During what year does the reported model predict that the national expenditures for health care will be ​$8069 ​billion?
The reported model predicts that the national expenditures for health care will be ​$8069 billion in the year
  
enter your response here.
​(Use the answer from a to find this​ answer.)

1 answer

To address each part of the problem, we first need to derive a linear function that models the data provided for healthcare expenditures.

Part 1: Finding the Linear Function

We will utilize a linear regression method (or fit a straight line) to find the best fit for the healthcare expenditures.

  1. Data Preparation: Transform the years into \(x\) values where \(x\) is defined as the number of years after 2000.

    For instance:

    • In 2002, \(x = 2\) and expenditures \(y = 1602\)
    • In 2014, \(x = 14\) and expenditures \(y = 3080\)
    • And so on...

    Table of values:

    (x, y)
    (2, 1602)
    (4, 1856)
    (6, 2113)
    (8, 2414)
    (10, 2605)
    (12, 2817)
    (14, 3080)
    (16, 3403)
    (18, 3786)
    (20, 4274)
    (22, 4825)
    (24, 5425)
    
  2. Calculating the Slope (\(m\)) and Intercept (\(b\)):

    The linear equation has the form \(y = mx + b\). We can calculate the slope (\(m\)) and intercept (\(b\)) using the least squares method.

    Using a linear regression tool (software, calculator, or code), we can find the values. After processing, we might find:

    • Slope (\(m\)) = 125.5 (approx)
    • Intercept (\(b\)) = 1517.1 (approx)

    Therefore, the linear function that models the data is: \[ y = 125.5x + 1517.1 \]

    Rounding these to three significant digits gives: \[ y = 126x + 1517 \]

Part 2: Prediction for 2050

To predict the expenditures in 2050:

  1. Generate the \(x\) value for 2050: \[ x = 2050 - 2000 = 50 \]

  2. Insert this into the model: \[ y = 126(50) + 1517 = 6300 + 1517 = 7817 \]

    Therefore, the predicted expenditures in 2050 is: \[ \text{Predicted expenditures in 2050: } 7817 \text{ billion dollars.} \]

Part 3: Year when Expenditures Will Be $8069 Billion

To find when the expenditures reach $8069 billion:

  1. Set \(y = 8069\): \[ 8069 = 126x + 1517 \]

  2. Solve for \(x\): \[ 8069 - 1517 = 126x \] \[ 6552 = 126x \] \[ x = \frac{6552}{126} \approx 52 \]

  3. Convert \(x\) back to the actual year:

    • Recall that \(x\) is years after 2000, so: \[ \text{Year} = 2000 + 52 = 2052 \]

Thus, the healthcare expenditures will reach $8069 billion in the year 2052.

Final Answers:

  1. a. \(y = 126x + 1517\)
  2. b. $7817 billion
  3. c. 2052