Final answer:
To calculate the amount of money in the savings account on your 18th birthday, we can use the formula for compound interest. The amount of money will be closest to $75,089.
Step-by-step explanation:
To calculate the amount of money in the savings account on your 18th birthday, we can use the formula for compound interest. Since your grandparents have been depositing $100 every year, we need to calculate the future value of these payments with 9% interest compounded annually for 17 years (from your 1st to 18th birthday).
Using the formula:
Future Value = P(1 + r/n)^(nt)
Where P is the principal amount (initial deposit), r is the annual interest rate, n is the number of times the interest is compounded per year, and t is the number of years.
In this case, P = 100, r = 9%, n = 1 (compounded annually), and t = 17. Plugging in these values, we get:
Future Value = 100(1 + 0.09/1)^(1*17) = $75,089
Therefore, the amount of money in your savings account on your 18th birthday will be closest to $75,089.