Drill. The drill is a review of the concept of slope and y-intercept in relation to a real-world situation. In this problem the slope represents the change in monthly charges for each additional video that is rented. The y-intercept represents the charge when zero videos are rented.
Introduction - Analyzing Scatter plots - Students should follow the instructions on the worksheet and compare their lines of best fit with a partner. One method to determine an association is to draw an oval that includes all the data points. The thinner and more oblong the oval, the stranger the association. Students may disagree on graph #4. Discuss the impact of the outlier (22,5).
Exploration - Students may be introduced to finding equations for lines of best fit by using two data points to determine their equation. If they are reading data points from a graph, be sure to emphasize the importance of reading the scales on the x- and y-axis. Students should also be instructed to find a line of best fit using the graphing calculator. Have students work with a partner to answer questions on "Biking Home". Discuss the limits of using a line of best fit. Complete "Dentists for the Future". Be sure to review window settings appropriate for the data and how to graph scatter plots and equation on the same graph. Demonstrate how to calculate the line of best fit in the stat menu.
Class Discussion - Ask students to explain the equation form (ax +b) and how it relates to (mx +b). Discuss the differences between students' estimates and the calculated lines of best fit.
Additional problems - The data collection activities provided give the students an opportunity to generate and analyze their own data