The unpaid balance at the start of a 30-day billing cycle was $740.98. A purchase of $51.43 was made on day 15. No payment was made during the billing cycle and a late fee of $36 was charged to the account on day 27. Find the unpaid balance at the end of the billing cycle. Assume that the annual interest rate on a credit card is 20.77% and interest is calculated by the average daily balance method. The unpaid balance at the end of the billing cycle is $7. (Round to the nearest cent as needed.)