1. 7.1 Draw Scatter Plots & Best-Fitting Lines

2. Vocabulary Scatter plot: a graph of a set of data pairs (___, ___)
Positive correlation: y tends to ________ as x ________
Negative correlation: y tends to ________ as x ________

3. More Vocabulary r x y x y x y x y x y -1 1
Correlation coefficient: (r), a number from ___ to ___ that measures how well a line fits a set of data pairs (x, y). x y x y x y x y x y r -1 1

4. If “r” is…
-.956
.899 1 -1
0.5
-0.6

5. Mathematical Formula for Computing “r”
Thank goodness your calc can do this!

6. More Vocabulary
Best-fitting line: line that lies as close as possible to all the data points
Linear regression: a method for finding the equation of the best-fitting line, or regression, which expresses the linear relationship between the independent variable x and the dependent variable, y, e.g. y = _________

7. Guided Practice for Ex.1, p. 248
1) 2)

8. Example 2: Approximate the best-fitting line
Scatterplot
Best-Fit Line EQ
Best-Fit Line Graph
See Handout

9. Start Homework
See Agenda