2.5 Correlation & Best-Fitting Lines

Today’s objectives:1. I will use linear regression to

approximate the best-fitting line for a set of data.

Line of Best Fit Plot the data given in the table as

ordered pairs on a coordinate plane. This is a scatter plot.

Draw a line that models the data with the same # of points above and below the line.

Choose two points on the line and estimate their coordinates. Don’t have to be original data points.

Write the equation of the line.

Type of Correlation Positive Correlation: if the data fits a

line with a positive slope, it represents positive correlation.

Negative Correlation: if the data fits a line with a negative slope, it represents negative correlation.

Relatively No Correlation: if the data doesn’t fit a line with a positive or negative slope, it represents relatively no correlation.

Correlation Strength:Correlation Coefficient (r)

If r >0 but close to 1, there is a strong positive correlation.

If r >0 but close to 0, there is a weak positive correlation.

If r < 0 but close to -1, there is a strong negative correlation.

If r < 0 but close to 0, there is a weak negative correlation.