In this activity, students will identify outliers that are influential with respect to the least-squares regression line. Students will describe the role of the location of a point relative to the other data in determining whether that point has influence on the least-squares regression line.

• Students will identify outliers that are influential with respect to the least-squares regression line.
• Students will describe the role of the location of a point relative to the other data in determining whether that point has influence on the least-squares regression.
• Student will use appropriate tools strategically (CCSS Mathematical Practices).

• centroid
• influence
• least-squares regression line
• residual
• scatter plot

• Students will investigate the relationship between the location of an outlier relative to the main pattern of a scatter plot and the influence that point exerts on the least-squares regression line.
• Students will manipulate a designated point and observe how its location alters an existing least-squares line.
• Students will manipulate a line fixed through the centroid of the scatter plot and observe how various slopes affect the sum of squared residuals.