Scatterplots and Correlation

Question 1

What is a Response Variable?

Answer 1

The variable that measures the outcome of a study.

Question 2

What is an Explanatory Variable?

Answer 2

The variable that may explain or influence changes in a response variable.

Question 3

What is a Scatterplot?

Answer 3

A graphical representation of data that shows the relationship between two quantitative variables measured on the same individuals.

Question 4

When examining a Scatterplot, what three characteristics are most telling of the relationship between the variables?

Answer 4

1. Direction
2. Form
3. Strength

Question 5

In the context of scatterplots, what is Correlation, and how is it calculated?

Answer 5

Correlation measures the direction and strength of the linear relationship between two quantitative variables.

“Standardize x and y. The correlation r is an average of the products of the standardized x and the standardized y for all the individuals. The average here divides by one fewer than the number of individuals.”