A person is 21 years old and plans on retiring at age 55. This person is going to invest $50 each month into an IRA that is expected to earn 2.5% interest, compounded monthly. How much more money, rounded to the nearest dollar, is needed per month to reach a retirement savings goal of $100,000?

A spreadsheet was used to calculate the correct answer. Your answer may vary slightly depending on the technology used.

$50
$56
$106
$156