In all problems involving days, a 360-day year is assumed. When annual rates are requested as an answer, express the rate as a per- centage, correct to three decimal places. Round dollar amounts to the nearest cent. 49. If $3,000 is loaned for 4 months at a 4.5% annual rate, how much interest is earned? 50. If $5,000 is loaned for 9 months at a 6.2% annual rate, how much interest is earned? 51. How much interest will you have to pay for a credit card bal- ance of $554 that is 1 month overdue, if a 20% annual rate is charged? 52. A department store charges an 18% annual rate for overdue accounts. How much interest will be owed on an $835 account that is 2 months overdue? 53. A loan of $7,260 was repaid at the end of 8 months. What size repayment check (principal and interest) was written, if an 8% annual rate of interest was charged? 54. A loan of $10,000 was repaid at the end of 6 months. What amount (principal and interest) was repaid, if a 6.5% annual rate of interest was charged? 55. A loan of $4,000 was repaid at the end of 10 months with a check for $4,270. What annual rate of interest was charged? 61. What annual interest rate is earned by a 13-week T-bill with a maturity value of $1,000 that sells for $989.37?