A variable that we purposefully change or manipulate is called the independent variable. The thing that changes in response is called the dependent variable. This creates a cause and effect relationship.
Medicare Eligibility Requirements. To be entitled to Medicare, you must be a U.S. citizen or a permanent legal resident, and answer yes to at least one (1) of the following questions:
Retirees and those still working. To receive full Medicare coverage at 65, you (or your spouse) have to have earned enough credits to be eligible for Social Security. Each $1,260 you earn equals one credit, but you can only earn a maximum of four each year.