Patricia estimated the future CPI using a scatter plot. The line of best fit's equation is y = 5x + 120. For the year 2030, the x-value is 382, and the estimated CPI is 2030.
To address the three parts of the problem:
Part A: Equation for the Line of Best Fit
The equation for the line of best fit is typically written in slope-intercept form: y = mx + b, where m is the slope and b is the y-intercept.
Given the points (0,120) and (20,220), we can find the slope (m):
![\[ m = \frac{\text{change in } y}{\text{change in } x} = (220 - 120)/(20 - 0) = (100)/(20) = 5 \]](https://img.qammunity.org/2024/formulas/mathematics/middle-school/e8paiupbhkefxmnfiz1fzm7bpti30w68tv.png)
Now, we can use the slope and one of the points (e.g., (0,120)) to find the y-intercept (b):
![\[ b = y - mx = 120 - 5 * 0 = 120 \]](https://img.qammunity.org/2024/formulas/mathematics/middle-school/ddpuc9dcyykq8oev5lzmtxbxqz68havwtx.png)
So, the equation for the line of best fit is y = 5x + 120.
Part B: X-Value for the Year 2030
To find the x-value for the year 2030, we need to substitute the year (2030) into the equation and solve for x:
2030 = 5x + 120
5x = 2030 - 120
5x = 1910
![\[ x = (1910)/(5) = 382 \]](https://img.qammunity.org/2024/formulas/mathematics/middle-school/4ndqsxws2kb1vahtemo4p1bf8z9megethz.png)
Part C: Estimate CPI for the Year 2030
Now that we have the x-value (382) for the year 2030, we can use it in the equation:
y = 5x + 120
![\[ \text{CPI}_(2030) = 5 * 382 + 120 \]](https://img.qammunity.org/2024/formulas/mathematics/middle-school/qfaawrn7q53don5139085dufvfept6t689.png)
![\[ \text{CPI}_(2030) = 1910 + 120 \]](https://img.qammunity.org/2024/formulas/mathematics/middle-school/h6jyw33tfj1ykt9hn94kj6ezkylkwy4ncz.png)
![\[ \text{CPI}_(2030) = 2030 \]](https://img.qammunity.org/2024/formulas/mathematics/middle-school/opv82bksmjus461xilhvs5h95rsidesdma.png)
Therefore, the estimated CPI for the year 2030 is 2030.