Question

A correlation of r = .85 is found between weekly sales of firewood and cough
drops over a 1-year period. Which of the following is true?

• (a) There is a pretty strong positive linear relationship between sales of firewood and cough drops.
• (b) Fire must be the cause of coughing.
• (c) Temperature is a possible lurking variable that is “behind” this relationship.
• (d) Both (a) and (c) are true.
• (e) None of the above

Answer 1

r = 0.85 showing there is pretty strong positive linear relationship hence option A) is correct.

Temperature also affects both sales of firewood and cough drops hence option C) is also correct.

Hence, Option D) both a and c are true is the answer.