First, we need to find the interest. This is given by
![\begin{gathered} \text{Interest}=(\text{ Balance)}*(Rate)*(Time) \\ \text{Interest}=(\text{ \$615.87)}*(0.08)*((1)/(12)) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/rmt1izc0e88f0x4mgzd3yemlsgw0oogrs7.png)
which gives
![\text{Interest}=\text{ \$4.1058}](https://img.qammunity.org/2023/formulas/mathematics/college/r51gd8ndsjilo903r0hialk00eig3oku3b.png)
a) What is the amount of the final payment?
The final payment is given by
![\begin{gathered} \text{ Final payment = Balance+Interest} \\ \text{ Final payment =}615.87+4.1058 \\ \text{ Final payment =}619.9758 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/gj4gvdun1qa0tfprudjb686ictja6inarq.png)
Then, the answer is $619.9758
b) How much does he save by paying the loan off early?
Since the loan is for 12 months, the total payment is
![\begin{gathered} \text{Total payment=12}*156.60 \\ \text{Total payment=}1879.20 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/79mqrb77dz3ruhukjjpf055hn6x29ky6ue.png)
Therefore, the amount saved is given by
![\begin{gathered} \text{Amount saved = Total payment-Months payed-Final payment} \\ \text{Amount saved = }1879.20-(8*156.60)-619.9758 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/bk5i2xhtcmj3cc1nedl4ha6zo0bjaoqcbb.png)
which gives
![\begin{gathered} \text{Amount saved = }1879.20-1252.80-619.9758 \\ \text{Amount saved = }6.4242 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/sf9840ekv4do7j04gkncskly7d3w4ztzyp.png)
Therefore, the answer is $6.4242 saved