Step-by-step explanation:
We are to find the monthly payment and interest on the loan for the purchase of the car.
To do so, we will list some parameters to be used

then

also, the rate

So we can apply the formula

simplifying further, we will have the monthly payment to be

Thus,
The monthly payment is $552.37
For the second part of the question, we are to get the total interest for the loan, to do so, we will multiply the monthly payments by the number of times and then subtract the original worth of the car
So we will have

Then we will subtract the value of P from the value obtained

Therefore, the interest for the loan is $3878.76