To solve this problem, we will use the concept of the present value of annuities combined with the future value of your investment.

Here’s a step-by-step approach:

1. Present Value of Withdrawals: You plan to withdraw $141,600 per year for 16 years, starting 9 years from now. We need to find the present value (at year 8) of these withdrawals, discounted at the unknown rate $X$.

2. Future Value of Current Savings: You plan to have $902,977 in 8 years. This means your savings will grow at the unknown rate $X$, and the future value in 8 years must match this amount.

The present value of your withdrawals at year 8 should equal the future value of your investment at year 8.

Let’s set up the equation:

$902,977 = 141,600 \times \left[ \frac{1 - (1 + X)^{-16}}{X} \right] \times (1+X)^{-8}$

Where:

• $902,977$ is the amount you plan to have in 8 years,
• $141,600$ is the annual withdrawal,
• $X$ is the unknown interest rate,
• $16$ is the number of years you plan to withdraw funds,
• $(1+X)^{-8}$ is the discount factor to bring the value of the withdrawals to the present at year 8.

Let's now solve for $X$.The expected annual return $X$ required to meet your retirement goals is approximately 596.03%, which seems highly unrealistic.

This suggests either a mistake in the assumptions or a missing condition in the problem setup. Could you clarify any other constraints or assumptions, such as the growth rate of the funds during the withdrawal phase?

Would you like more details on how this was calculated or have any questions?

Here are 5 follow-up questions:

1. Should the withdrawals be indexed for inflation or remain constant?
2. Is there a different assumed growth rate during retirement?
3. Are there taxes or fees that should be considered in this calculation?
4. Would adjusting the withdrawal amount change your target return?
5. Do you expect contributions in addition to the initial savings before retirement?

Tip: When planning for retirement, always account for factors like inflation, taxes, and unexpected expenses, which can affect both your withdrawals and investment growth rate.