Answer: Unit of account; Store of value; Medium of exchange.
Step-by-step explanation:
Sam can easily know that the price of the computer system is more than the price of the vacation. This is a Unit of Account.
Unit of account is measuring of the value of a product against another in terms of a specific currency.
Sam has $1,537 in his checking account. This is a Store of value.
Store of value means an asset or money can be saved and retrieved at a later time, for future use.
Sam writes a check for $1,299 is a medium of exchange.
Medium of exchange is used to facilitate trade between parties. He exchanged money for the computer.