Linear and NonLinear Relations

Linear and NonLinear Relations

Recall: A line of best fit is a straight line that comes closest to the points on a scatter plot.
Question: What if the relationship we are trying to model is not linear?

Example 1: Plot each set of ordered pairs on the grids provided below.

A line of best fit must be used on this graph
b)

A curve of best fit must be used on this graph.

Example 2: Why is a line of best fit not a good model for the data in each graph?

There aren`t enough data points to determine the correlation
It seems to follow a non-linear pattern
The data doesn`t seem to follow any pattern (data is scattered all over)
Example 3: Draw a curve of best fit for each set of data.

Summary:
• Data that form a relatively straight line on a scatter plot indicate a linear correlation between the variables.
• A line can model a linear relationship, but is usually a poor model for a non-linear relationship.

• You can use a line or curve of best fit to interpolate values within a data set.
• You can extrapolate values beyond the range of a set of data by extending a line or curve of best fit.