The outstanding balance on Bill's credit card account is $3900. The bank issuing the credit card is charging 10.1%/year compounded monthly. If Bill decides to pay off his balance in equal monthly installments at the end of each month for the next 18 months, how much will be his monthly payment? (Round your answer to the nearest cent.) What is the effective rate of interest the bank is charging Bill? (Round your answer to three decimal places.)