1. Regression and Median Fit Lines
Algebra I Section 4-6
Regression and Median Fit Lines

2. Vocabulary Best-fit line: line used to predict data Linear Regression: way to determine best-fit line use the graphing calculator Correlation coefficient: ( letter r) displayed on calculator closer the value is to 1 or -1 the better

3. Use the graphing calculators to make the scatter plot and to calculate the best-fitting line.
Turn the calculator on - STAT PLOT ON
[ STAT ] button
Edit …
you will see a table with 3 columns labeled L1, L2, L3

4. Enter the x values into L1
Enter the y values into L2
STAT PLOT your data (zoom 9)
To find the linear regression equation:
[ STAT ] - CALC - LinReg(ax+b) – enter (x2)
write down the values of a and b to two decimal places

5. 1. The table shows the amount of money made by movies in the United States. Use the graphing calculator to write the equation for the best-fit line for that data. List the correlation coefficient. ** use x = 0 for 2000, x = 1 for 2001, ….
Year
2000
2001
2002
2003
2004
2005
2006
2007
Income ($billions)
7.48
8.13
9.19
9.35
9.27
8.95
9.25
9.65

6. Assignment:
Worksheet 4 – 6 (need graphing calculator) Page 273 – – 28 Evens 32, 38 42, 44 Test - Friday