Final answer:
To find the lump sum that must be invested at 4% semiannually for college tuition in 9 years, we can use the future value of a single sum formula.
Step-by-step explanation:
To find the lump sum that must be invested at 4% semiannually, we can use the future value of a single sum formula:
FV = PV(1 + r/n)^(nt)
Where:
FV = Future Value (the amount of money needed in 9 years)
PV = Present Value (the lump sum to be invested today)
r = Annual interest rate (4%, but since it's semiannually compounded, we divide it by 2 to get 2%)
n = Number of compounding periods per year (2, since it's semiannually compounded)
t = Number of years (9)
Plugging in the values, we get:
FV = PV(1 + 0.02)^(2*9)
Now we can solve for PV:
PV = FV / (1 + 0.02)^(2*9)
Substituting the given future value of $30,300, we get:
PV = $30,300 / (1 + 0.02)^(2*9)
Simplifying the calculation:
PV = $30,300 / (1.02)^18
PV = $30,300 / 1.4286
PV ≈ $21,227.30
Therefore, a lump sum of approximately $21,227.30 must be invested at 4% semiannually.