1. Regression and Median-Fit Lines
LESSON 4–6
Regression and Median-Fit Lines

2. The table shows the average weight for given heights
The table shows the average weight for given heights. Does the data have a positive or negative correlation?
5-Minute Check 1

3. Refer to the scatter plot of Jessica’s visits to the park
Refer to the scatter plot of Jessica’s visits to the park. Use the points (20, 9) and (100, 4) to write the slope-intercept form of an equation for a line of fit.
5-Minute Check 3

4. Refer to the scatter plot of Jessica’s visits to the park
Refer to the scatter plot of Jessica’s visits to the park. Predict the number of times Jessica will go to the park when the temperature is 50 degrees.
5-Minute Check 4

5. What is an equation of the line of fit that passes through the points at (2, –1) and (–1, –7)?
5-Minute Check 5

6. Mathematical Processes A.1(E), A.1(G)
Targeted TEKS
A.4(A) Calculate, using technology, the correlation coefficient between two quantitative variables and interpret this quantity as a measure of the strength
of the linear association.
A.4(C) Write, with and without technology,
linear functions that provide a reasonable fit to data to estimate solutions and make predictions for real-world problems.
Mathematical Processes
A.1(E), A.1(G)
TEKS

7. correlation coefficient residual median-fit line
best-fit line
linear regression
correlation coefficient
residual
median-fit line
Vocabulary

8. Best-Fit Line
EARNINGS The table shows Ariana’s hourly earnings for the years 2009–2015. Use a graphing calculator to write an equation for the best-fit line for the data. Find and interpret the correlation coefficient. Let x be the number of years since 2008.
Example 1

9. BIOLOGY 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.
Example 1

10. Use Interpolation and Extrapolation
BOWLING The table shows the points earned by the top ten bowlers in a tournament. How many points did the 15th-ranked bowler earn?
Use a graphing calculator to write an equation of the best-fit line for the data. Then use the equation to approximate the missing value.
Example 2

11. TRAVEL 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. How many passengers should the airline expect to go to Kelley’s Island in 2115?
A passengers
B passengers
C passengers
D passengers
Example 2

12. Use the data from the table and a median-fit line to estimate the number of passengers the airline will have in 2015.
A passengers
B passengers
C passengers
D passengers
Example 3

13. Regression and Median-Fit Lines
LESSON 4–6
Regression and Median-Fit Lines