Choose the letter of the correct answer, no need for solution.

Which of the following correlation coefficients reflects the strongest correlation between X and Y ?

1. r= 0.99
2. r= 0.05
3. r=-1
4. r=0

Which of the following correlation coefficients reflects the weakest correlation between X and Y ?

1. r=-0.92
2. r=0.65
3. r=0.15
4. r=0.88

Which of the following correlation coefficients is consistent with the statement: "The greater number of stories there are in a building, the higher the height of the building (in meters)"?

1. r= 0
2. r= -1
3. r= 0.75
4. r= -0.75

Which of the following correlation coefficients is consistent with the statement: "Higher levels of smoking are associated with lower life expectancy"?

1. r= -1.5
2. r= 0.5
3. r= 0
4. r= -0.5

Suppose a researcher found a significant relationship between the number of COVID-19 cases and greenhouse gas emissions in 2020. What is the appropriate reason for such relationship to possibly exist?

A.The relationship between the number of COVID-19 cases and greenhouse gas emissions may be coincidental.

B.There may be a complexity of interrelationships among many variables.

C.There is a direct cause-and-effect relationship between the number of COVID-19 cases and greenhouse gas emissions.

D.The relationship between the number of COVID-19 cases and greenhouse gas emissions may be caused by a third variable.