Answer:
A variable interest rate (sometimes called an “adjustable” or a “floating” rate) is an interest rate on a loan or security that fluctuates over time because it is based on an underlying benchmark interest rate or index that changes periodically.
A tiered-rate account is a checking or savings account that pays interest at increasingly higher rates as the account balance increases. Each tier consists of a range of account balances and interest rates earned by the customer if his or her balance falls within that range