R24 Selected Answers and SolutionsSelected Answers and Solutions
55 There are 4 choices for fi rst place. There are
3 choices that remain for second place. There are
2 choices that remain for third place. There is
1 choice that remains for fourth place. Since 4 · 3 ·
2 · 1 = 24, there are 24 possible ways in which the
four bands can be ordered.- 720 9. 901 11. 121
1313 Find consecutive whole numbers, starting
with 1, that have a product of 720. Since 1 · 2 · 3 · 4
· 5 · 6 = 720, there are 6 members in the Coughlin
family. - Sample answer: The number of ways you can
order 3 books on a shelf is 3 · 2 · 1 or 6. 17. 20
things taken 4 at a time; Sample answer: To fi nd
P(20, 4), multiply 20 · 19 · 18 · 17. 19. C 21. 56
Pages 452–455 Lesson 8-2B
11 There is a _^12 chance of landing on tails and a _^16
chance of rolling a 3. _^12 × _^16 = _ 1213.^16 5. 245 7. 481 9. ^38 11. 245 13. 28792
1515 There are a total of 5 +^7 +^4 + 4 or 20 students.
P(green) = 204 or ^15 ; P(brown after green) = 197
P(green then brown) = ^15 · 197 or 957
17. 767 19.^12 19 21a. 11.76% 21b. 24.64%
23. 134 ; dependent event; The fi rst coin is not replaced.
2525 The probability of the fi rst player choosing a tile
with the same number of dots on each side is 287. If
each player were to draw such a tile, both the
number of favorable outcomes and the number of
possible outcomes would reduce by one for each
person, resulting in the following product:
_^7
28 ·^
_^6
27 ·^_^5
26 ·^_^4
25 or_^1
585- Sample answer: Raul used the method for
dependent events. Spinning the spinner twice
represents two independent events. The probability
of getting an even number is _^25 each time. 29. Both
independent events and dependent events are
compound events. Independent events do not affect
each other. Dependent events affect each other. - I 33. G 35. _^23
Pages 460–462 Lesson 8-3A
11 a. The experimental probability is
number of times heads appears
___number of tosses = _^2850 or^14 _ 25.
b. The theoretical probability is
__favorable outcomes
possible outcomes^ =^_^1
2. c. The experimental
probability, _^1425 or 56%, is close to its theoretical
probability of _^12 or 50%.3a. _ 51 ; The experimental probability, _^15 or 20%, is
close to its theoretical probability of _^16 or about 17%.
3b. 10 _^9 ; The experimental probability, _ 109 or 90%, is
close to its theoretical probability of _^56 or about 83%.
55 a. The theoretical probability is
__favorable outcomes
possible outcomes^ =^_ (^1)
3.
b. The experimental probability P(A) =
number of times landing on A
_number of spins = 256. The experimental
probability P(C) =
number of times landing on C
number of spins = ^1350.
c.
CA
B
The experimental probability
of landing on section A is 256 ,
or about ^14. The experimental
probability of landing on
section B is 10050 , or ^12. The
experimental probability of
landing on section C is ^1350 , or about _^14. So, section B
should be one half of the spinner and sections A
and C should each be one fourth of the spinner.
- 72 9. Sample answer: Both probabilities are
ratios that compare the number of favorable
outcomes to the total number of outcomes.
Experimental probability is the result of an
experiment. Theoretical probability is what is
expected to happen. 11. H 13. _^27
Pages 464–465 Lesson 8-3C PSI- Sample answer: Results could vary greatly.
- No; Sample answer: the experiment produces
about 1–2 correct answers, so using a spinner with
4 sections is not a good way to answer a 5-question
multiple-choice quiz. 5. 30
77 If there were 160 students surveyed, half, or
50%, of the students would be 80 students. 40% of
the students preferred a dunking booth; this is a
little less than 50%. Therefore, the number close to,
but smaller than 80, or 65 students is the most
reasonable choice for the answer. - 31 11. $70; Sample answer: Round $95 to $100.
10% of $100 is $10, so 20% would be $20.
$100 - $20 = $80, which is closest to $70.
Pages 469–471 Lesson 8-3E
11 a. 33% of the teens said they would save their
money. Let n be the number of students that would
save their money.
n = 0.33 · 60,000 Write the percentage equation with 33% as a decimal.
n = 19,800 Simplify.
So, about 19,800 teens surveyed said they would
save their money. b. Write a proportion. Let p be
the number of students that would buy a music CD.
R01_R42_EM_SelAns_895130.indd R24 1/18/10 9:51 AM