Audrey purchases a $3,099 riding lawn mower using a deferred payment plan. The plan allows the customer to make no down payment, and there is no payment at all for 4 months. If the entire $3,099 is paid in full before the 4 months is up, there is no interest. If it is not paid in full within the 4 months, there is a finance charge with an APR of 21.6% applied each month going back to the first month. If Audrey makes the full payment two weeks after the 4 months expired, what is the finance charge?