Answer :
Answer:
(a) $897.72: 26 yr
$1526.49: 10 yr
(b) See below.
(c) x = 705
more, $705, longer it will take
Step-by-step explanation:
Given equation:
[tex]t=16.708 \ln \left(\dfrac{x}{x-705}\right)[/tex]
where:
- t = term of the mortgage (in years)
- x = monthly payment plan (in dollars)
Part (a)
[tex]\begin{aligned}x=897.72 \implies t& =16.708 \ln \left(\dfrac{897.72}{897.72-705}\right)\\& =16.708 \ln \left(4.65815691...\right)\\&=16.708(1.53861985...)\\&=25.70726...\\&=26\; \rm years\end{aligned}[/tex]
[tex]\begin{aligned}x=1526.49 \implies t& =16.708 \ln \left(\dfrac{1526.49}{1526.49-705}\right)\\& =16.708 \ln \left(1.85819669...\right)\\& =16.708(0.619606496...)\\&=10.352385...\\&=10 \; \rm years\end{aligned}[/tex]
Part (b)
To approximate the total amounts paid (in dollars) over the term of the mortgage, multiply the monthly payment by the term.
Please note I have provided two calculations per monthly payment:
(1) by using the exact term, and (2) using the rounded term from part (a).
[tex]\implies \$897.72 \times 25.7072605... \times 12 =\$276935.06[/tex]
[tex]\implies \$897.72 \times 26 \times 12=\$280088.64[/tex]
[tex]\implies \$1526.49 \times 10.3523853... \times 12=\$189633.75[/tex]
[tex]\implies \$1526.49 \times 10 \times 12 =\$183178.80[/tex]
To calculate the amount of interest costs (in dollars) in each case, subtract $150,000 from the total amounts paid:
[tex]\$897.72\implies 276935.06-150000=\$126935.06[/tex]
[tex]\$897.72 \implies 280088.64-150000=\$130088.64[/tex]
[tex]\$1526.49 \implies 189633.75-150000=\$39633.75[/tex]
[tex]\$1526.49\implies 183178.80-150000=\$33178.80[/tex]
Part (c)
The natural logarithm of a negative number cannot be taken.
Therefore, x > 705.
So the vertical asymptote for the model is:
- x = 705
The monthly payment must be more than $705, and the closer to this value the payment is, the longer it will take to pay off the mortgage.