1. 4-6 Regression Lines Goal:
Use a graphing calculator to find the equation of the line of best fit.
Eligible Content:
A / A / A / A / A / A / A

2. Vocabulary
Correlation Coefficient – tells you if the correlation is positive or negative and how close your equation is to modeling the data.
The closer the correlation coefficient is to 1 or -1, the more closely the equation models the data.
Get calculators ready: 2nd  0  DiagnosticsOn

3. Using a Graphing Calculator
The calculator can get a much more exact answer, and it is faster!!! Follow the steps…

4. Example #1
The table shows Megan’s hourly earnings for the years 2001–2007.
Use a graphing calculator to write an equation for the best-fit line for the data. Let x = 0 represent 2000.
Name the correlation coefficient.
The equation for the best-fit line is y = 1.21x
The correlation coefficient is 0.98

5. Example #2
The table shows the average body temperature in degrees Celsius of nine insects at a given temperature.
Use a graphing calculator to write the equation for the best-fit line for that data.
Name the correlation coefficient.
y = 0.95x ;

6. Example #3
The table shows the points earned by the top ten bowlers in a tournament.
Use a graphing calculator to write an equation for the best-fit line for the data.
How many points did the 15th-ranked bowler earn?
y = -7.87x
83 points

7. An air taxi keeps track of how many passengers it carries to various islands. The table shows the number of passengers who have traveled to Kelley’s Island in previous years. Use a graphing calculator to find the equation of the line of best fit. Let x = 0 represent 2000.
y = 68.71x

8. Practice Page 259 #1-3 Directions:
Find the equation of best fit using your calculator.
Find the correlation coefficient

9. Homework
Pages #4-6 – write equation and correlation coefficient #7-8 – do all parts of question!