A survey was conducted in 20 counties to determine the percentage of teenagers who had used marijuana and other drugs.Data shown on the following scatterplot indicate a correlation of 0.972 between the percent of teens who have used marijuana and the percent who have used other drugs.Describe the association.
A)Strong curved relation in a positive direction
B)Weak linear relation in a positive direction
C)Strong linear relation in a positive direction
D)Strong nonlinear relation in a positive direction
E)No evidence of relation

Question

A survey was conducted in 20 counties to determine the percentage of teenagers who had used marijuana and other drugs.Data shown on the following scatterplot indicate a correlation of 0.972 between the percent of teens who have used marijuana and the percent who have used other drugs.Describe the association. 
A)Strong curved relation in a positive direction 
B)Weak linear relation in a positive direction 
C)Strong linear relation in a positive direction 
D)Strong nonlinear relation in a positive direction 
E)No evidence of relation

Quizplus · Accepted Answer

The correlation coefficient of 0.972 indicates a very strong positive linear relationship between the percentage of teens who have used marijuana and the percentage who have used other drugs. This means that as the percentage of teens who use marijuana increases, the percentage of teens who use other drugs also tends to increase proportionally at a nearly constant rate. The scatterplot supports this conclusion, as the points are tightly clustered around a straight line that slopes upward to the right.

A Survey Was Conducted in 20 Counties to Determine the Percentage