Final answer:
Using the formula for continuous compounding, A = Pert, the calculation shows that after 12 years, Robert's initial $800 investment at a 5.5% annual interest rate will grow to approximately $1548.40.
Step-by-step explanation:
To calculate the future value of an investment with continuous compounding, we use the formula A = Pert, where P is the principal amount, r is the annual interest rate, t is the time in years, and e is the base of the natural logarithm, approximately equal to 2.71828.
For Robert's investment of $800 at an annual interest rate of 5.5% (or 0.055 when expressed as a decimal) compounded continuously for 12 years, the formula becomes:
A = 800e0.055*12
Next, we calculate the value inside the exponent:
0.055*12 = 0.66
Now we raise e to the power of 0.66:
e0.66 ≈ 1.93550
And finally we multiply by the principal:
A = 800 * 1.93550 ≈ $1548.40
After 12 years, Robert will have approximately $1548.40 in his account.