8. Use the "rule of 72" to estimate the doubling time (in years) for the interest rate, and then calculate it exactly. (Round your answers to two decimal places.)8%compounded annually.

"rule of 72"yr

exact answeryr

10. Since 2007, a particular fund returned13.1%compounded monthly. How much would a$5000investment in this fund have been worth after2years? (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.) $3500annually at7%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 earning5%to accumulate$6000after 10 years.

$

18. Determine the payment to amortize the debt. (Round your answer to the nearest cent.) Quarterly payments on$13,500at3.1%for 6 years.

$

19. Find the unpaid balance on the debt. (Round your answer to the nearest cent.) After7years of monthly payments on$170,000at4%for 25 years.

$

20. The super prize in a contest is $10 million. This prize will be paid out in equal yearly payments over the next20years. If the prize money is guaranteed by AAA bonds yielding4%and is placed into an escrow account when the contest is announced 1 year before the first payment, how much do the contest sponsors have to deposit in the escrow account? (Round your answer to the nearest cent.)

$