Question

Create four graphs showing the following four types of relationships between variables (Cozby p 79): positive linear relationship, negative linear relationship, curvilinear relationship, no relationship. You need to choose two variables for each different type of graph. In other words, you cannot use the same variables for all four graph. You may not use any of the examples in the textbook.

Answer 1

Positive correlation 800 700 600 2 500 SAT score 400 300 200 100 0 0 1 2 3 4 5 5 7 8 Preparation time

As the preparation time increase the SAT score increased. The points have aligned from bottom left to top right

Negative correlation 700 600 500 400 SAT score 300 200 100 0 0 2 4 6 8 10 12 Number of hours of sleep Correlation coefficient = -0.692

With increase in number of hours of sleep the SAT score decreased. The points have aligned from top left to bottom right

Curvillinear Correlation 6 5 4 Height of the ball 3 N 1 0 1 2 3 4 5 6 Number of minutes after throwing the ball in to air

Throw a ball in to air the height of the ball from the ground is curvillinear

No Correlation 900 800 700 600 500 400 SAT score 300 200 100 0 0 20 40 60 80 100 120 Amount spend on coaching in dollars

The points have scattered all around