May enters into a contract to purchase a Jet Ski. She is required to pay $225 per month for 3 yrs and the final payment 2 months later of $500. If the interest rate is  J_{12} = 18%:

a) What is the value of the Jet Ski

b) What was the total interest of the loan?

My answers are: a) $6,507.61
and b) $1592.39

Is this correct??