DCN Maths Online

CORRELATION COEFFICIENT

CORRELATION COEFFICIENT: See how variables move together at a glance.

The correlation coefficient is a statistical measure that shows the strength and direction of the relationship between two variables.

It is usually denoted by r.

Its value ranges from –1 to +1.

Interpretation:

r = +1 → Perfect positive relationship (as one increases, the other increases).

r = –1 → Perfect negative relationship (as one increases, the other decreases).

r = 0 → No linear relationship.

Example:
If study time and exam scores have r = 0.85, it means there is a strong positive relationship — students who study more tend to score higher.