> John will enter college 6 years from now, and spend 4 years in
> college. The current annual cost of college education is $25,000 and
> is expected to rise 5% each year. Thus, the first college payment is
> due 6 years from now and the last payment is due 9 years from now.
Using your numbers, the annual costs can be estimated as follows:
C8: =fv(5%,6,0,-25000)
C9: =fv(5%,7,0,-25000) or =C8*(1+5%)
C10: =fv(5%,8,0,-25000) or =C9*(1+5%)
C11: =fv(5%,9,0,-25000) or =C10*(1+5%)
> Dad would like to make 10 annual investments beginning now and ending
> 9 years from now such that the total value of his investments and
[quoted text clipped - 5 lines]
> expenes and account balances for each year
> b) What is the first year's investment (the answer is $8797.55).
Intuiting your model, one approach might be:
A2:A11: year number (0-9)
B2: initial investment (8797.55)
B3: =B2*(1+6%)
Copy B3 to B4:B11
C2:C11: withdrawals (C8:C11 as above)
D2:D11: porfolio balance
D2: =B2
D3: =D2*(1+8%) + B3 - C3
Copy D3 to D4:D11
However, I believe that has an off-by-one-year error. If we assume
that investments and withdrawals are both at the beginning of the year
(you wrote the first payment is "due in 6 years"), it does not make
sense to invest in the 9th year.
With that in mind, I would clear B11 (9th-year investment); thus, you
are making only 9 investments. Then, if we interpolate B2 (initial
investment) by increasing and decreasing appropriately until D11
(portfolio balance) is the smallest positive value (near zero), we get
$9686.80.
(Alternatively, you could use Excel Solver to derive B2.)
Notes: This does not take income tax into account. Also, some of
your assumptions are dubious. But you can refine this model as you
see fit.
Kevin Smith - 21 Feb 2007 05:47 GMT
Terrific - you are awesome. Much appreciated !!!!!
> > John will enter college 6 years from now, and spend 4 years in
> > college. The current annual cost of college education is $25,000 and
[quoted text clipped - 46 lines]
> your assumptions are dubious. But you can refine this model as you
> see fit.