
Jonathan W. answered 11/10/14
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1. At 21, it's worth $1234000. At 22, it's worth $1234000 + 0.077*$1234000 = $1234000(1+0.077) = $1234000(1+0.077)22-21. Following this pattern, at 27 it's $1234000(1+0.077)27-21. You're never too old for that!
2. $19000 = R(1-(1+0.050/12)-5*12)/(0.050/12), by this amortization payment formula, where R is the monthly payment amount.
3. I believe that if R is the yearly saving amount and each year you compound after saving, then the amount in the account goes from $50000 to $50000+R to ($50000+R)(1+0.07) =$50000(1+0.07) + R(1+0.07) in the first year, $50000(1+0.07)2 + R((1+0.07)2 + (1+0.07)) in the second year, and so on with a geometric series in 1+0.07, and after 30 years you solve $50000(1+0.07)30 + R(1+0.07)((1+0.07)30-1)/0.07 = $1000000. Now if instead each year you compound before saving, you solve $50000(1+0.07)30 + R((1+0.07)30-1)/0.07 = $1000000, I believe.