Answer:
d may cause f.
Explanation:
Here are the options
d must not cause f.
f must cause d.
d must cause f.
d may cause f.
Correlation is a statistical measure used to measure the relationship that exists between two variables.
1. Positive correlation : it mean that the two variables move in the same direction. If one variable increases, the other variable also increases.
For example, there should be a positive correlation between quantity supplied and price
When there is a positive correlation, the graph of the variables is upward sloping
2. Negative correlation : it mean that the two variables move in different direction. If one variable increases, the other variable decreases.
For example, there should be a negative correlation between quantity demanded and price
When there is a negative correlation, the graph of the variables is downward sloping
3. Zero correlation : there is no relationship between the variables