It is important to understand the relationship between two variables. With quantitative data, this primarily consists of using a scatterplot and the correlation coefficient to describe four key characteristics of the relationship. This module describes how to construct a scatterplot, calculate a correlation coefficient, and how to use these results to prepare a synthetic description of the relationship between two quantitative variables.

After completing this module, you should be able to ...

  1. Construct a scatterplot with R.
  2. Know when it is appropriate to calculation a correlation coefficient.
  3. Calculate a correlation coefficient with R.
  4. Construct a succinct written summary that addresses the four key characteristics (form, direction, outliers, and strength) of the relationship between two quantitative variables.

Preparation for Class

You should read this and watch these videos:


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