1 The weight of a fire fighter would be an example of a continuous variable; since a fire fighter's weight could take on any value between 150 and 250 pounds.  Suppose we flip a coin and count the number of heads. The number of heads could be any integer value between 0 and plus infinity.
A postal code is a series of letters and/or digits appended to a postal address for the purpose of sorting mail. Once postal codes were introduced, other applications became possible. In February 2005, 117 of the 190 member countries of the Universal Postal Union had postal code systems.
The Fast Lane Answer. A ZIP Code is a group of five or nine numbers that are added to a postal address to assist the sorting of mail. A complete, 9-digit ZIP Code, including its additional four digits (called a ZIP+4 Code), is the designation of a delivery route. In other words, regular ZIP Codes indicate which USPS employees will be servicing the address, while the ZIP+4 will tell you which delivery route it will be on.