1.3.3 Explanatory and Response Variables (page 19)
2.1.1 Scatterplots for paired data (pages 46-48)
Lesson
In a scatterplot, we are going to graph two quantitative variables together. One variable will be on the x-axis and the other on the y-axis.
Recall our definition of explanatory and response variables:
Explanatory Variable (also known as independent variable): the variable that influences the other variable
Response Variable (also known as dependent variable): the variable that is influenced by the explanatory variable
When you compare two quantitative variables, the first thing you need to do is determine which of the two variables is the explanatory variable and which is the response variable. Once you know these, label the x-axis as the explanatory variable and the y-axis as your response variable.
Once your labels are created,
Take one datapoint and identify its value for the explanatory variable, then find that point on the x-axis
From the same datapoint, identify its value for the response variable, then find that point on the y-axis
Imagine a vertical line from your x-value and a horizontal line from your y-value. Where they meet is the location of your datapoint
Do this for all datapoints, and you have a scatterplot!