Final answer:
To calculate the time required to double an investment at an annual interest rate of 4.50 percent, use the Rule of 72, which gives approximately 16 years as the answer.
Step-by-step explanation:
To determine how long it will take for an investment to double with an annual interest rate, you can use the Rule of 72, which is a simplified formula to estimate the number of years required to double the invested money at a given annual rate of return. You divide 72 by the annual interest rate.
In this case, with an interest rate of 4.50 percent, you would calculate the doubling time as follows: 72 ÷ 4.5 = 16 years (approximately).
Therefore, it would take about 16 years for your $290 investment in a mutual fund to double, assuming a 4.50 percent annual interest rate and that the interest is compounded annually.