Final answer:
Compound interest is the function that would calculate the final value of an investment of $250.
Step-by-step explanation:
The function that would calculate the final value of an investment of $250 is Compound Interest. Compound interest is an interest rate calculation on the principal plus the accumulated interest over time. It takes into account the time period for which the investment is held and the interest rate. With compound interest, the final value will be higher than the initial investment due to the compounding effect.