What does a correlation coefficient of -1 indicate?

What does a correlation coefficient of -1 indicate?

• A. Perfect negative relationship
• B. No relationship
• C. Perfect positive relationship
• D. Moderate negative relationship

Answer: (A)

The correlation coefficient describes the strength and direction of a linear relationship between two variables. A value of -1 is the extreme end of the scale and signals a perfect negative linear relationship: as one variable increases, the other decreases in exact proportion, so all data points lie on a straight line with a negative slope. For example, if one variable is twice the other in a consistent, noiseless way, you’d see this perfect inverse pattern. This differs from no relationship, which would produce a correlation near zero with points scattered widely and no clear line. A perfect positive relationship would yield a correlation of +1, where both variables increase together along a straight line. A moderate negative relationship would have a correlation somewhere between 0 and -1 (such as around -0.5), indicating a noticeable but not perfect inverse association.

The correlation coefficient describes the strength and direction of a linear relationship between two variables. A value of -1 is the extreme end of the scale and signals a perfect negative linear relationship: as one variable increases, the other decreases in exact proportion, so all data points lie on a straight line with a negative slope. For example, if one variable is twice the other in a consistent, noiseless way, you’d see this perfect inverse pattern.

This differs from no relationship, which would produce a correlation near zero with points scattered widely and no clear line. A perfect positive relationship would yield a correlation of +1, where both variables increase together along a straight line. A moderate negative relationship would have a correlation somewhere between 0 and -1 (such as around -0.5), indicating a noticeable but not perfect inverse association.