Cook security systems has a $37,500 line of credit, which charges an annual percentage rate of prime rate plus 4%. the starting balance on october 1 was $9,700. on october 4 they made a payment of $1,600. on october 13 the business borrowed $2,100, and on october 19 they borrowed $4,800. if the current prime rate is 8%, what is the new balance (in $)? (round your answer to the nearest cent. )