14._Chapter_14_Slides--Scatterplots

What is a scatterplot used for?

A scatterplot is used to show the relationship between quantitative variables measured on the same individuals.

How do you create a scatterplot?

To make a scatterplot, take measurements of two variables, X and Y, for each individual and plot the points (x, y) on a graph.

What indicates a positive direction in a scatterplot?

If as x increases, y also tends to increase, resulting in a slope that goes up.

What indicates a negative direction in a scatterplot?

If as x increases, y tends to decrease, resulting in a slope that goes down.

What is the correlation coefficient symbol?

The correlation coefficient is represented by the symbol r.

What range does the correlation coefficient (r) fall within?

The correlation coefficient (r) values range from -1 to 1.

What does it mean if r is close to 1?

If r is close to 1, it signifies a strong positive relationship between the variables.

What is a misleading strength in a scatterplot?

A misleading strength occurs when the relationship appears stronger than it actually is, often due to extending the axes.

Define linear relationship in the context of scatterplots.

A linear relationship is when the points plotted can be closely approximated by a straight line.

Why does correlation not imply causation?

Causation implies some correlation, but correlation alone does not prove that one variable causes the other.