To determine how much Derek needs to deposit annually into his retirement account starting on his 29th birthday and ending on his 65th birthday, we can use the future value of an annuity formula.
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Identify the variables:
- Future Value (FV) = $3,816,699.00
- Interest rate (r) = 10% or 0.10
- Number of deposits (n) = 65 - 29 = 36 years
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Future Value of an Annuity Formula: The future value of an annuity formula is: \[ FV = PMT \times \frac{(1 + r)^n - 1}{r} \] where:
- \( PMT \) = annual payment (which we need to find)
- \( r \) = interest rate per period
- \( n \) = number of periods
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Rearranging for PMT: We can rearrange the formula to find \( PMT \): \[ PMT = \frac{FV \times r}{(1 + r)^n - 1} \]
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Substituting known values:
- \( FV = 3,816,699.00 \)
- \( r = 0.10 \)
- \( n = 36 \)
Therefore, substituting into the formula: \[ PMT = \frac{3,816,699 \times 0.10}{(1 + 0.10)^{36} - 1} \]
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Calculating \((1 + 0.10)^{36}\): \[ (1.10)^{36} \approx 36.194 \]
- Thus, \( (1.10)^{36} - 1 \approx 36.194 - 1 \approx 35.194 \)
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Substituting back into the PMT formula: \[ PMT = \frac{3,816,699 \times 0.10}{35.194} \approx \frac{381,669.90}{35.194} \approx 10,828.099 \]
Therefore, the annual deposit \( PMT \approx 10,828.10 \).
So, Derek must make annual deposits of approximately $10,828.10 starting on his 29th birthday and ending on his 65th birthday in order to accumulate $3,816,699 by the time he turns 65.