Linear Data, Equations and Least Squares Regression

Overview

Allows students to use the Internet to find their own real-life data
to plot and analyze.

Materials and Equipment

- Computer Lab
- Internet Access and Browser
- Microsoft Excel
- File Storage (floppy disks or networked file server)

Learning Objectives

- Select and document linear data to investigate
- Evaluate the data for accuracy and validity
- Plot data and create a chart using Excel
- Interpret the negative slope of a line as a rate of change in the context of real-life data
- Interpret the y-intercept of a line in the context of real-life data
- Interpret the meaning of the correlation coefficient of the least squares regression line

Guiding Questions

- What factors did you consider when selecting sets of data that might be linear in nature when graphed?
- What mathematical knowledge did you need to be able to select linear data?
- What additional knowledge and skills are required to find such data on the Web?
- What types of Web searches (keyword, Boolean, other?) did you perform?
- What caused you trouble? Why do you think it was a problem for you?
- How would you explain to a younger student the characteristics of data sets that might be linear in nature when graphed? How would you help them find such data on the Web?
- What do the slope, y-intercept, and correlation coefficient tell you about your data?

Lesson Outline

- Pair off students. Have groups research on the Web for data that is linear in nature when graphed. Encourage students to find one set of data with a positive slope and one with a negative slope. Make sure students appropriately document their sources.
- Have students enter the data into a new Excel spreadsheet and create a Scatter chart similar to Lesson One. Have students save their spreadsheet.
- Use the chart and data to facilitate answers to the Guiding Questions. Pay particular attention to the selection process, and the analysis of the slope, y-intercept and correlation coefficient.

Assessment

- Homework or Quiz based on Guiding Questions
- Internet Research (Research Worksheet)
- Excel Spreadsheet (Spreadsheet Rubric)