1. Linear Regression
Special Topics

2. Regression Line
A regression line is a straight line that describes how a response variable y changes as an explanatory variable x changes.
We often use a regression line to predict the value of y.
Regression, unlike correlation, requires that we have an explanatory and a response variable.

3. Example

4. Least –Squares Regression Line (LSRL)
The Least Squares Regression Line (LSRL) is a mathematical model suitable for a linear trend.
LSRL - of y on x is the line that makes the sum of squares of the vertical distance of the data points to the line as small as possible. (error)
error = observed – predicted

5. Example

6. Demonstration
LSRL equation: = mx + b
is the predicted response
b is the y-intercept
m is the slope

7. To Calculate:

8. In-Class Practice

9. Homework
Worksheet