In this lesson, students plot data about automobile mileage and interpret the meaning of the slope and y-intercept
of the least squares regression line. By examining the graphical
representation of the data, students analyze the meaning of the slope
and y-intercept of the line and put those meanings in the context of the real-life application.
The activity is very similar to that in Lesson Five of this Unit
Plan. However, by graphing the data in a different format, the students
will produce a line with a positive slope in this activity, while the
line in Lesson Five had a negative slope. Doing both lessons allows
students to investigate how changing the independent variable affects
the resulting graph and equation.