Answer:
$6,573.08
Step-by-step explanation:
first we need to determine the present value (in 20 years) of Bilbo's retirement distributions:
present value = monthly distribution x annuity factor (PV, 0.6667%, 240 periods) = $26,000 x 119.51872 = $3,107,486.72
now we need to find the present value (in 20 years) of Frodo's inheritance:
present value = $850,000 / (1 + 8%)²⁰ = $182,365.98
this means that in 20 years, Bilbo must have saved $3,107,486.72 + $182,365.98 = $3,289,852.70
but that is not all, he also needs $675,000 in 15 years:
in 15 years, Bilbo's savings account will have monthly contribution x annuity factor (FV, 0.75%, 180 periods) = $2,300 x 378.40577 = $870,333.27
that means that Bilbo will have $870,333.27 - $675,000 = $220,333.27
in 15 more years, the $220,333.27 will be worth: $220,333.27 x (1 + 9%)¹⁵ = $802,560.07
so Bilbo is $3,289,852.70 - $802,560.07 = $2,487,292.63 short
his monthly contribution to his savings plan should be:
$2,487,292.63 = monthly payment x annuity factor (FV, 0.75%, 180)
$2,487,292.63 = monthly payment x 378.40577
monthly payment = $2,487,292.63 / 378.40577 = $6,573.08