Give an example of an association between two variables that have a causal relationship
A scientist in a dairy factory tries four different packaging materials for blocks of cheese and measures their shelf life. The packaging material might influence shelf life, but the shelf life cannot influence the packaging material used. The relationship is therefore causal.
// A bank manager is concerned with the number of customers whose accounts are overdrawn. Half of the accounts that become overdrawn in one week are randomly selected and the manager telephones the customer to offer advice. Any difference between the mean account balances after two months of the overdrawn accounts that did and did not receive advice can be causally attributed to the phone calls.
If two variables are causally related, it is possible to conclude that changes to the explanatory variable, X, will have a direct impact on Y.