Question

section 4.1: correlation
two variables have a linear relationship if the data tend to cluster around a straight line when plotted on a scatterplot.

check your understanding
for each of the following scatterplots, state the type of association that is exhibited: choices: positive linear, negative linear, positive nonlinear, negative nonlinear, weak linear

Explanation:

• Scatterplot a: Data clusters along a downward-sloping straight line, so it has a negative linear association.
• Scatterplot b: Data clusters along an upward-sloping straight line, so it has a positive linear association.
• Scatterplot c: Data loosely follows an upward-sloping straight line with weak clustering, so it has a weak linear association.
• Scatterplot d: Data shows no clear linear or nonlinear trend, with very weak clustering, so it has a weak linear association.
• Scatterplot e: Data follows a downward-sloping curved pattern, so it has a negative nonlinear association.

Answer:

a. negative linear
b. positive linear
c. weak linear
d. weak linear
e. negative nonlinear