Kate bought a new car priced at $21,300 with 15% down and the balance in equal payments over 4 years at 7% compounded monthly. Determine the size of the monthly payments? The answer is $433.65 please show me the steps

PV = payment (1 - (1+i)^-n )/i

you should know this formula

balance is .85(21300) = 18105
i = .07/12 = .0058333...
n = 48

18105 = payment (1 - 1.00583333..^-48)/.0058333..
18105 = payment ( 41.76020173)
payment = 18105/41.76... = $ 433.55

( I carried all the decimals my calculator could hold, they must have rounded off before they got to the final answer, not a good idea if you have a calculator)

To determine the size of the monthly payments, we can use the formula for calculating the monthly payment of a loan:

M = P [(i*(1+i)^n) / ((1+i)^n - 1)]

Where:
M = Monthly payment
P = Principal amount (the price of the car minus the down payment)
i = Monthly interest rate (annual interest rate divided by 12 and expressed as a decimal)
n = Total number of monthly payments (number of years multiplied by 12)

Step 1: Calculate the principal amount P
Kate made a 15% down payment, so the principal amount P can be calculated as 85% of the car price.

P = 0.85 * $21,300
P = $18,105

Step 2: Calculate the monthly interest rate i
The annual interest rate is 7%, which needs to be divided by 100 to convert it to a decimal. Since the interest is compounded monthly, we need to divide the annual interest rate by 12.

i = (7 / 100) / 12
i = 0.00583

Step 3: Calculate the total number of monthly payments n
The loan term is 4 years, which needs to be multiplied by 12 to get the total number of monthly payments.

n = 4 * 12
n = 48

Step 4: Plug the values into the formula to calculate the monthly payment M

M = $18,105 [(0.00583*(1+0.00583)^48) / ((1+0.00583)^48 - 1)]

Calculating this equation should give you the answer, which is approximately $433.65.

Please note that the formula assumes equal payments over the duration of the loan.