A science instructor assigns a group of students to investigate the linear relationship between the pH of the water of a river and its water's hardness (measured in grains).Some students wrote these conclusions: "My correlation of -0.85 shows that there is almost no association between pH of the water and water's hardness." Is the interpretation of the correlation appropriate?
A)Yes: a correlation of -0.85 shows a weak relation in a negative direction.
B)No: correlation is always positive.
C)No: a correlation of -0.85 shows a strong relation in a negative direction.
D)Yes: pH and hardness of water do not have the same units.
E)No: the pH and the hardness of the water are data collected from the same river.

Question

Quizplus · Accepted Answer

A correlation of -0.85 indicates a strong relation in a negative direction, meaning that as the pH of the water decreases (becomes more acidic), the water's hardness increases. Therefore, the interpretation provided by the students is not appropriate.

A Science Instructor Assigns a Group of Students to Investigate