.
It works in this way: they withdraw $12000 at the beginning of every quarter, and the account is compounded quarterly
at the nominal rate of 8% per year.
The general formula to calculate the starting amount at the account is
X = .
In this formula, W is the regular withdrawal per quarter, W = $12000; the factual quarterly compounding rate
is r = 0.08/4 = 0.02, p = 1 + 0.02 = 1.02, and the number of payment periods is n = 30 years * 4 quarters = 120. So
X = = 555,149.96 dollars. It is the ANSWER to the problem's question [1].
The answer to question [2] is = 0.39 dollars.
The answer to question [3] is 30*4*12000 = 1,440,000 dollars.
Regarding question [4], I do not understand precisely its meaning.
Solved.
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See my lessons in this site associated with annuity saving plans and retirement plans
- Ordinary Annuity saving plans and geometric progressions
- Annuity Due saving plans and geometric progressions
- Solved problems on Ordinary Annuity saving plans
- Withdrawing a certain amount of money periodically from a compounded saving account (*)
- Miscellaneous problems on retirement plans
and especially lesson marked (*) in the list as the most relevant to the given problem.