9. Find the effective rate of the compound interest rate or investment. (Round your answer to two decimal places.) 28% compounded monthly. [Note: This rate is a typical credit card interest rate, often stated as 2.3% per month.]

10. Since 2007, a particular fund returned 13.8% compounded monthly. How much would a $5000 investment in this fund have been worth after 3 years? (Round your answer to the nearest cent.)

11. In the following ordinary annuity, the interest is compounded with each payment, and the payment is made at the end of the compounding period. Find the accumulated amount of the annuity. (Round your answer to the nearest cent.)

$3500 annually at 6% for 10 years.

12. In the following ordinary annuity, the interest is compounded with each payment, and the payment is made at the end of the compounding period. Find the required payment for the sinking fund. (Round your answer to the nearest cent.)

Monthly deposits earning 4% to accumulate $7000 after 10 years.