Answer:
$11,215.24
Explanation:
After retirement:
Annual Withdrawal = $100,000
Period = 20 years
Annual Interest Rate = 7%
Amount required at retirement = $100,000 * PVIFA(7%, 20)
Amount required at retirement = $100,000 * (1 - (1/1.07)^20) / 0.07
Amount required at retirement = $100,000 * 10.5940
Amount required at retirement = $1,059,400
Before retirement:
Period = 30 years
Annual Deposit * FVIFA(7%, 30) = $1,059,400
Annual Deposit * (1.07^30 - 1) / 0.07 = $1,059,400
Annual Deposit * 94.46079 = $1,059,400
Annual Deposit = $11,215.24
So, you should contribute $11,215.24 each year into your retirement fund.