**Correlation** measures the strength and direction of the relationship between two variables. A positive correlation means that as one variable increases, the other also increases. A negative correlation means that as one variable increases, the other decreases.
There are three types of correlation:
Example 1: There is a positive correlation between the number of hours studied and the grades received on a test. As the number of hours studied increases, the test score tends to increase as well.
As hours studied → increases, grade → increases (positive correlation).
Example 2: There is a negative correlation between the number of hours spent watching TV and the grades received on a test. As the number of hours spent watching TV increases, the test score tends to decrease.
As hours watching TV → increases, grade → decreases (negative correlation).
Example 3: There is no correlation between a person’s shoe size and their test scores. A person’s shoe size has no impact on their performance on a test.
As shoe size → increases, grade → does not change (no correlation).
Identify the type of correlation based on the following example:
As the amount of rainfall increases, the number of people visiting the beach decreases.
Hint: Think about whether the two variables are moving in the same direction (positive), opposite directions (negative), or if there's no relationship at all (no correlation).