IMathAS-libretexts

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?

There is a pretty strong positive linear relationship between sales of firewood and cough drops.
Fire must be the cause of coughing.
Temperature is a possible lurking variable that is â€œbehindâ€ this relationship.
Both (a) and (c) are true.
None of the above.