Scatter Plots

Scatter plots A graph of points which show the relationship between two quantitative variables measured on the same individual. Such as…

Scatter plot vARIABLES The x-axis value; it is the independent variable. The y-axis value; it is the dependent variable. RESPONSE EXPLANATORY

So, which variable is which??? The explanatory variable is… The response variable is… And what does the graph tell you???

Scatter plots Here you see a scatter plot… The explanatory variable is … The response variable is … As the x values increase, what is happening to the y values? This is an example of negative association.

Words which describe Scatter Plots Strength Strong—points follow a tight pattern. Weak—points are scattered widely. Form Straight-line (linear) Curved

Words which describe scatter plots Positively Associated: As the x value goes up, the y value goes up; as the x value goes down, the y value goes down. Negatively Associated: As the x value goes up, the y value goes down; as the x value goes down, the y value goes up.

How they look Positively Associated Negatively Associated

Homework This is due on Wed. 2/29-Thu. 3/1 Finish the lists of strong relationships and weak relationships. Remember you will be choosing one from each list to use for your surveys. This is due on Wed. 2/29-Thu. 3/1