If the change in one variable effect, the difference in another variable is called correlation.
TYPES OF CORRELATION:
1. Positive Correlation
2. Negative Correlation
1) Positive Correlation: Increase in one variable lead to increase the other variable or decrease in one variable leads to a reduction in the other variable is called positive correlation.
Ex: Heights and weights of a group of persons
2) Negative Correlation: Increase in one variable lead to a decrease in the other variable or decrease in one variable point to an increase in the other variable is called negative correlation.
Ex: Supply and price of a commodity