How Many Drivers? Investigating the Slope-Intercept Form of a Line

Published on
06/09/2008

Activity Overview

In this activity, students will be introduced to the slope-intercept form of a linear equation. They will recognize the effects of changes in the slope and y-intercept on the graph of a line. Students will use the Transformation Graphing application to find an approximate linear model of the actual data. They will use the guess-and-check strategy, manipulate the values of the slope and y-intercept to determine the line of best fit.

See the attached PDF files for detailed instructions for this activity

Print pages 1 - 8 from the attached activity PDF file for the class

During the Activity

Distribute the printed pages to the class.

Follow the Activity procedures:

Plot graphs for the linear equation y = mx + b on the calculator and observe how the graph changes with variations in m and b values

Write an hypothesis on the effect of m and b on the graph of a line

Start the Transformation Graphing Application and graph the equation y = Ax + B

Set the starting values for the coefficients and the increment and observe the change in the coefficients.

Compare the results with the hypothesis

Using the hypothesis, identify graphs of equations and answer questions; verify using the calculator

Prepare a scatter plot showing the relationship between the population and number of licensed drivers; identify the independent variable and the pattern in the relationship

Estimate the values of the slope and y-intercept for the linear model

Use the estimates to graph lines; adjust values of the coefficients to obtain a reasonable model that fits the data

After the Activity

Students' answer questions on the homework page.

Review student results:

As a class, discuss questions that appeared to be more challenging