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:
Eligibility to start Medicare coverage normally begins the month you turn 65, or if you're disabled at any age. You can sign up for Medicare three months before you turn 65 even if you're not yet getting retirement benefits.