Education Technology

Exploring Bivariate Data

Published on 06/09/2008

Activity Overview

Students graph scatter plots and understand the concepts of correlation and least-squares regression. They also perform transformations to achieve linearity in the data plot.

Before the Activity

Install the Statistics with List Editor application on the calculator using one of these two methods:

  • TI Connect™, a TI Connectivity Cable, and the Unit-to-Unit Link Cable
  • TI-Navigator™ "send to class" feature
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 59 - 78 from the attached PDF file for your class

During the Activity

Distribute the pages to the class.

Follow the Activity procedures:

  • Enter the heights of buildings in Philadelphia & New York City, and the year of their completion, as lists
  • Set up scatter plots for both sets and compare the graphs
  • Enter the car name, mileage per gallon, weight of car, and number of cylinders as lists
  • Find the simple linear correlation coefficient between mileage and weight, mileage and cylinder, cylinder and weight
  • Plot the data and observe the relationship
  • Plot a least-squares regression line through the data
  • Observe that the line does not fit the data sufficiently
  • Identify the outliers
  • Plot the data without the outlier point and observe that the line is close to the regression line
  • Calculate the Coefficient of Determination and the sum of squares regression and linearize the data
  • Perform different types of transformations and measure how well the line fits the transformed data
  • After the Activity

    Review student results:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary