Answer
The monthly payments are $\$732$
The interest is $\$5136$
Work Step by Step
We can use this formula to calculate the payments for a loan:
$PMT = \frac{P~(\frac{r}{n})}{[1-(1+\frac{r}{n})^{-nt}~]}$
$PMT$ is the amount of the regular payment
$P$ is the amount of the loan
$r$ is the interest rate
$n$ is the number of payments per year
$t$ is the number of years
$PMT = \frac{P~(\frac{r}{n})}{[1-(1+\frac{r}{n})^{-nt}~]}$
$PMT = \frac{(\$30,000)~(\frac{0.08}{12})}{[1-(1+\frac{0.08}{12})^{-(12)(4)}~]}$
$PMT = \$732$
The monthly payments are $\$732$
We can find the total amount paid.
$\$732 \times 48 = \$35,136$
The interest is the difference between the total amount paid and the amount of the loan.
$I = \$35,136 - \$30,000 = \$5136$
The interest is $\$5136$