You want to borrow $27,500 and can afford monthly payments of $650 for 48 months, but no more. Assume monthly compounding. What is the highest APR rate you can afford

Respuesta :

Answer:

Max APR=6.34%

Explanation:

Present Value of Payments

If someone borrows an amount PV and will make regular payments of R dollars, then the relation between them is

[tex]PV=F_a\cdot R[/tex]

Where

[tex]\displaystyle F_a=\frac{1-(1+i)^{-n}}{i}[/tex]

We know the maximum value for R is $650, thus we can know the minimum value for Fa with:

[tex]\displaystyle F_a=\frac{PV}{R}=\frac{27,500}{650}=42.31[/tex]

It means that we need to find the value of i such that (for n=48):

[tex]\displaystyle \frac{1-(1+i)^{-48}}{i}=42.308[/tex]

This equation cannot be solved in terms of natural or algebraic functions. We need to find the best possible value of i by any numerical approximate method. Let's start off by setting i=0.01

[tex]\displaystyle \frac{1-(1+0.01)^{-48}}{0.01}=37.97[/tex]

It's too far away from the required value. Now we adjust to i=0.005

[tex]\displaystyle \frac{1-(1+0.005)^{-48}}{0.005}=42.58[/tex]

This is a much better value. A final iteration for i=0.00528 gives

[tex]\displaystyle \frac{1-(1+0.00528)^{-48}}{0.00528}=42.302[/tex]

This value is close enough to the required answer. Converting it tho APR:

[tex]i=0.00528\cdot 12\cdot 100=6.34\%[/tex]