Jing has a line of credit from her local bank with a limit of $10 000. On March 1 she owed $7265. From March 1 to June 30, she withdrew principal amounts of $3000 on April 10 and $500 on June 20. According to the line of credit agreement, Jing must make a regular payment of $200 on the 15th of each month. She has made these payments. Interest (including overdraft interest) is charged to the account on the last day of each month. On March 1, the interest rate was 9%, but it was changed to 8.5% effective May 15. Overdraft interest is 18% for any balance in excess of $10 000.
(a) Calculate the interest charges on March 31, April 30, May 31, and June 30.
(b) What is the account balance on June 30?