15. Compute the present value (principal) if the future value is $50,000 after 50 years at 6% compounded
annually.
$2,714.50
Chapter 16 Compound Interest 335
Assignment 16.2 Continued
6% 4 1 5 6%
1 3 50 5 50 periods $50,000 4 18.42015 5 $2,714.42 or $50,000 3 0.05429 5 $2,714.50
4% 4 4 5 1% $27,400 4 1.06152 5 $25,812.04 or $27,400 3 0.94205 5 $25,812.17
4 356 periods1
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2
8% 4 1 5 8% $6,000 4 1.58687 5 $3,781.03 or $6,000 3 0.63017 5 $3,781.02
1 3 6 5 6 periods $6,000 2 $3,781.02 5 $2,218.98
6% 4 2 5 3% $30,000 4 1.19405 5 $25,124.58 or $30,000 3 0.83748 5 $25,124.40
2 3 3 5 6 periods
9% 4 12 5 0.75% $5,000 4 1.16989 5 $4,273.91 or $5,000 3 0.85478 5 $4,273.90
21 months 5 21 periods
8% 4 2 5 4% $11,100 4 1.42331 5 $7,798.72 or $11,100 3 0.70259 5 $7,798.75
2 359 periods $11,100 2 $7,798.75 5 $3,301.254
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Score for B (32)
C (40 points) Business Applications. Find the present value (principal) or the compound interest,
as indicated. Use either Table 16-1, Table 16-2, or a calculator. Round answers to the nearest cent.
(4 points for each correct answer)
16. Ben Mahaffy needs to buy another used logging truck. His mother will loan him part of the money at
only 4% compounded quarterly. If Ben estimates that he will be able to repay his mother a total of
$27,400 in years, how much can he borrow from her today?
$25,812.17
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17. Six years ago, Eleanor Baker invested money at 8% compounded annually. Today she received a check for
$6,000 that represented her total payment of principal and interest. Compute the amount of the interest
that she earned.
$2,218.98
18. Lee Oman wants to have $30,000 available at the end of 3 years to help purchase a computerized metal
lathe for his machine shop. If he can invest money at 6% compounded semiannually, how much should
he invest?
$25,124.40
19. As part of their financial planning, Janice Garcia’s grandparents made monetary gifts to each of their
grandchildren. In addition, Janice’s grandfather told her that, if she would save part of her gift for at least
a year, he would pay her interest of 9% compounded monthly. Janice decided to save just enough so that
she would have $5,000 at the end of 21 months, when she will be 16 years old. How much should she
save?
$4,273.90
20. Erin Blackstone estimated that she would need $11,100 in years to buy new equipment for her pottery
shop. Having extra cash, she invested money in an extremely safe investment that advertised a return of
8% compounded semiannually. Erin invested just enough money to end up with the $11,100. How much
of the $11,100 did Erin earn on her investment?
$3,301.25
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