To be or not to be... linear
The student will determine the correlation between two variables. They will graph ordered pairs on a coordinate plane, determine a best fit line, find slope and intercepts, and write the equation of a line. This lesson plan is geared for both 8th grade math and algebra.
A lesson plan for grades 8–12 Mathematics
Learning outcomes
- Students will understand, identify, and interpret positive, negative, and no correlation for scatter plots.
- Students will be able to graph ordered pairs on a coordinate plane.
- Students will be able to find the slope of a line given the graph.
- Students will correctly find X and Y intercepts from a graph.
- Given the graph of a linear equation students will determine the equation of the line in three forms (slope-intercept, point-slope, and standard).
Teacher planning
Time required for lesson
2 hours
Materials/resources
- Graph paper
- Rulers - small and large may be needed
- Pencils
- Data collection sheets: list format and table format.
Pre-activities
- Students should have been introduced to the concepts of the coordinate plane, graphing linear equations, slope, intercepts, and slope-intercept form.
- Students should be competent in plotting points and data collection.
Activities
- Students will pick two variables that they think may have a relationship. For Example: Height Vs. Weight, Time at mall Vs. Money spent, Foot size Vs. How high you can jump, Fingernail length Vs. Finger length, etc.
- Students then need to collect data (the more the merrier). The students/teacher may choose the method that is used to have students collect the data. The teacher may assign the collection process as a homework activity or it could be done during class. Have students collect data in a table or list format (see attached worksheets).
- Students then need to create a coordinate plane with the X and Y axis labeled with the two chosen variables, an appropriate numbering scale, and a title.
- Students must plot the given data collection points.
- After students have plotted their points, students will draw a best fit line for the given data. If the data has no correlation students may draw a line to continue with the forthcoming parts of the lesson.
- Once the best fit line is drawn students will gather the slope and intercepts from their line. They will then find the equation of the line.
- Finally, you may have a discussion concerning positive, negative, and no correlation or have students answer the given questions (see Question Sheet attachment)
Assessment
- Student graph and question sheet
- Student discussion in groups using any/all of the prompts given the Discussion Questions.
Supplemental information
Comments
I used this as a project for my Algebra students and they enjoyed it.
North Carolina Curriculum Alignment
Mathematics (2004)
Grade 8
- Goal 5: Algebra - The learner will understand and use linear relations and functions.
- Objective 5.02: Write an equation of a linear relationship given: two points, the slope and one point on the line, or the slope and y-intercept.
Grade 9–12 — Algebra 1
- Goal 4: Algebra - The learner will use relations and functions to solve problems.
- Objective 4.03: Use systems of linear equations or inequalities in two variables to model and solve problems. Solve using tables, graphs, and algebraic properties; justify results.
Grade 9–12 — Integrated Mathematics 1
- Goal 4: Algebra - The learner will use relations and functions to solve problems.
- Objective 4.01: Use linear functions or inequalities to model and solve problems; justify results.
- Solve using tables, graphs, and algebraic properties.
- Interpret the constants and coefficients in the context of the problem.
- Objective 4.01: Use linear functions or inequalities to model and solve problems; justify results.



