Statistical Analysis: Microsoft

4. How Variables Move Jointly: Correlation

IN THIS CHAPTER

Understanding Correlation 79

Using Correlation 95

Using TREND() for Multiple Regression 104

Moving on to Statistical Inference 112

Chapter 2, “How Values Cluster Together,” discussed how the values on one variable can tend to cluster together at an average of some sort—a mean, a median, or a mode. Chapter 3, “Variability: How Values Disperse,” discussed how the values of one variable fail to cluster together: how they disperse around a mean, as measured by the standard deviation and its close relative, the variance.

This chapter begins a look at how two or more variables covary: that is, how higher values on one variable are associated with higher values on another, and how lower ...