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114 ANSWERS TO ALL EXERCISES
CHAPTER 10 • CHAPTER CHAPTER10 • CHAPTER 10REFRESHING YOUR SKILLS FOR CHAPTER 10
1a. 5 ___ 10 � 1 __ 2 � 0.5
1b. 6 ___ 10 � 3 __ 5 � 0.6
1c. 4 ___ 10 � 2 __ 5 � 0.4
2a. 10 ___ 36 � 5 ___ 18 � 0.2 _
7
2b. 7 is most likely; probability of 7 is 6 __ 36 � 1 _ 6 � 0.1 _
6 .
2c. 18 ___ 36 � 1 __ 2 � 0.5
3a. 26 ___ 52 � 1 __ 2 � 0.5
3b. 8 ___ 52 � 2 ___ 13 � 0.154
3c. 2 ___ 52 � 1 ___ 26 � 0.038
4a. 155 ___ 600 � 31 ___ 120 � 0.258
4b. 275 ___ 600 � 11 ___ 24 � 0.458
4c. 500 ___ 600 � 5 __ 6 � 0.8 _
3
Answers to All Exercises
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ANSWERS TO ALL EXERCISES 115
LESSON 10.1
1a. 6 ___ 15 � 0.4; 7 ___ 15 � 0.4 _
6 ; 2 ___ 15 � 0.1 _ 3
1b. experimental
2a. 698 ____ 1424 � 0.490 2b. 477 ____ 1424 � 0.335
2c. 228 ___ 435 � 0.524
2d. 263 ___ 726 � 0.362
2e. theoretical
3a. 4 ___ 14 � 0.286
3b. 10 ___ 14 � 0.714
3c. 7.5 ___ 14 � 0.536
3d. 1.5 ___ 14 � 0.107
3e. 2 ___ 14 � 0.143
4a. 5 ___ 30 � 0.1 _ 6
4b. 97.5 ____ 100 � 0.975 4c. 31 ___ 36 � 0.86 _ 1
5a. experimental
5b. theoretical 5c. experimental
6a. Answers will vary.
6b. Possible answer: Use the random integer com mand on the calculator to simulate rolling a die.
6c. Answers will vary.
6d. Answers will vary. Sum your answers from 6c and divide the answer by 10.
6e. Answers will vary. Long-run averages should tend toward 6 turns in order to roll a 6.
7. Answers will vary. Each of these methods has shortcomings.
7. i. Middle numbers (3–7) are more common than getting only 1 or 2 or 8 or 9 heads in one trial of dropping pennies.
7. ii. Very few pencils will be at 0 or 1 in.; students throw away their pencils long before that.
7. iii. This is the best method, although books tend to open to pages that are used more than others.
8a. Answers will vary.
8b. The long-run experimental probability should show that 1 _ 6 of all rolls are a 3.
8c. Answers will vary. The points should level out to a straight line at y � 0.1
_ 6 . If you considered 5’s
instead of 3’s, the data should level out to the same value.
8d. Answers will vary but should be close to 1 _ 6 .
8e. P(3) � 1 _ 6 � 0.1 _
6 . There are six equally likely outcomes, and 3 is one of them, so the theoretical probability is 1 _ 6 .
9a. 4; 4 ___ 36 � 0. _
1
9b. 5; 5 ___ 36 � 0.13 _
8
9c. 10; 10 ___ 36 � 0.2 _
7
9d. 2; 2 ___ 36 � 0.0 _
5
9e. 10; 10 ___ 36 � 0.2 _
7
10a. 3 __ 5 , or 0.6 10b. 2 to 5
11a. 144 square units
11b. 44 square units
11c. 44 ___ 144 11d. 44 ___ 144 � 0.30 _
5
11e. 100 ___ 144 � 0.69 _
4
11f. 0; 0
12a. x � y � 6
12b. y
8
x
4
40 8
12c. 18 ___ 64 � 0.281
13a. 270
13b. 1380
13c. 270 ____ 1380 � 0.196
13d. 1110 ____ 1380 � 0.804
14a. 6 ___ 27 � 0. _
2 14b. 12 ___ 27 � 0. _
4
14c. 8 ___ 27 � 0. ___
296 14d. 1 ___ 27 � 0. ___
037
15a. 53 pm, at point C
15b. 0 pm, at point A, the nucleus
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116 ANSWERS TO ALL EXERCISES
15c. The probability starts at 0 at the nucleus, increases and peaks at a distance of 53 pm, and then decreases quickly, then more slowly, but never reaches 0.
16. x4 � 4x3y � 6x2y2 � 4xy3 � y4
17. log � ac2 ___
b �
18. x � 5000
19a. y
(–6, –1)
�5x � 4y � 26 3x � y � 15
x � 6y � �12
(2, 9)
(6, –3)
8
12
4
–4
AP1
B
C
x–4 4 8
19b. (2, 9), (�6, �1), (6, �3)
19c. 68 units2
20. a parabola with focus (3, 0) and directrix y � 6; y � � 1 __ 12 x2 + 1 _ 2 x + 9 _ 4
21a. Set i should have a larger standard deviation because the values are more spread out.
21b. i. __
x � 35, s � 22.3
21b. ii. __
x � 117, s � 3.5
21c. The original values of _
x and s are multiplied by 10.
21c. i. __
x � 350, s � 223.5
21c. ii. __
x � 1170, s � 35.4
21d. The original values of _
x are increased by 10, and the original values of s are unchanged.
21d. i. __
x � 45, s � 22.3
21d. ii. __
x � 127, s � 3.5
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ANSWERS TO ALL EXERCISES 117
LESSON 10.2
1. v1
v2
v1
v2
v1
v2
d1
d2d1
d2d1
d2d1
d2d1
d2d1
d2
e1
e2
e3
2. P(a) � 0.675; P(b) � 0.075; P(c) � 0.05; P(d) � 0.2; 1
3. P(a) � 0.7; P(b) � 0.3; P(c) � 0.18; P(d) � 0.4; P(e) � 0.8; P(f) � 0.2; P(g) � 0.08
4a. 1 __ 8 � 0.125
4b. 3 __ 8 � 0.375
4c. 2 __ 3 � 0. _
6
5a. The probability of selecting a junior given that a sophomore has already been selected; P(J2|S1)
5b. 13 ___ 20 � 0.6
5c. 7 ___ 10 � 0.7
6a. 182 ___ 420 � 0.4 _
3 ; 98 ___ 420 � 0.2 _
3 ; 98 ___ 420 � 0.2 _
3 ; 42 ___ 420 � 0.1
6b. No, because the probabilities of the four paths are not all the same
6c. 420 ____ 420 � 1
7a. 24
7b. 0.25
7c. 2 ___ 24 � 0.08 _
3
7d. 1 ___ 24 � 0.042
7e. 23 ___ 24 � 0.958
7f. 12 ___ 24 � 0.5
8a. H HH
HT
TH
TT
T
H
T
H
T
8b. HHH
HHTHTH
H
H
H
TH
TH
TH
T
T
H
T
T
HTTTHH
THTTTH
TTT
8c. HHHHHHHTHHTHHHTTHTHHHTHTHTTHHTTTTHHHTHHTTHTHTHTTTTHHTTHTTTTHTTTT
H
H
HH
TH
TH
TH
TH
TH
TH
TH
T
T
H
T
H
T
H
T
T
H
T
T
9a. 4
9b. 8
9c. 16
9d. 32
9e. 1024
9f. 2n
10a. 1 __ 2
10b. 1 __ 2
10c. independent
10d. Both statements reveal misconceptions about the probability of independent events. The probability of heads is always 1 _ 2 ; the coin does not remember how it landed previously.
11a. 1 ___ 16 � 0.0625
11b. 4 ___ 16 � 0.25
11c. 6 ___ 16 � 0.375
11d. 4 ___ 16 � 0.25
11e. 1 ___ 16 � 0.0625
11f. 1
11g. 0.3125
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118 ANSWERS TO ALL EXERCISES
12a. 0.05
0.95
0.08
0.92
0.07
0.93
M1
M2
M3
D 0.01
G 0.19
D 0.028
G 0.322
D 0.0315
G 0.4185
0.20
0.35
0.45
12b. 0.08
12c. 0.0695
12d. � 0.403
13a. 0.0289
13b. 0.9711
13c. 0.6889
13d. 0.9711
14. 6 ___ 16 � 0.375
15a. the probability that the roll is odd and it is a 3 or a 5; 1 _ 3 � 0.
_ 3
15b. the probability that the roll is a 3 or a 5 given that the roll is odd; 2 _ 3 � 0.
_ 6
15c. the probability that the roll is odd given that it is a 3 or a 5; 1
16a. 349 ____ 798 � 0.437
16b. 512 _____ 1424 � 0.360
16c. The events are dependent, because P(10th grade | female) � P(10th grade). The probability of choosing a 10th grader from the female students is greater than the probability of choosing a 10th grade student.
17. 64
18a. �3 � 2i
18b. 2 � 24i
18c. 18 ___ 29 � 16 ___ 29 i
19. P(orange) � 0.152; P(blue) � 0.45 _
6
20a. 50 ____ 110 � 0. __
45
20b. 120 ____ 230 � 0.522
21. 8 � __
2
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ANSWERS TO ALL EXERCISES 119
LESSON 10.3
1. 10% of the students are sophomores and not in advanced algebra. 15% are sophomores in advanced algebra. 12% are in advanced algebra but are not sophomores. 63% are neither sophomores nor in advanced algebra.
2a. 0.25 2b. 0.12
2c. 0.15 __________ 0.15 � 0.12 � 0. _
5
2d. 0.37
3.
50 75 60
315
Sophomore In advanced algebra
4. No. P(S) � P(A) � 0.25 � 0.27 � 0.0675, P(S and A) � 0.15. These must be equal if the events are independent.
5a. yes, because they do not overlap
5b. No. P(A and B) � 0. This would be the same as
P(A) � P(B) if they were independent.
6a.
71 55 220
74
French Music
6b. approximately 13% 6c. 74
7a.
0.12 0.08 0.32
0.48
A B
7b. i 0.08 7b. ii 0.60 7b. iii 0.48
8. 0 � P(A and B) � 0.4, 0.5 � P(A or B) � 0.9. The first dia gram shows P(A and B) � 0 and P(A or B) � 0.9. The second dia gram shows P(A and B) � 0.4 and P(A or B) � 0.5.
0.4 0.5
A B
0.40.1
AB
9.
0.075 0.175 0.12
0.63
Sophomore In advanced algebra
10a. yellow
10b. cyan
10c. white
10d. blue
10e. green
10f. black
11a.
0.18 0.045
0.015
0.14
0.105
0.06 0.035
Amber Bob
Carol
11b. 0.015 11c. 0.42
12a. 280 _____ 1500 � 0.18 _
6 12b. 775 _____ 1500 � 0.51 _
6
12c. 145 ____ 355 � 0.408 12d. 145 ____ 775 � 0.187
13. approximately 77
14. 324 _____ 15625 � 0.021
15a. 3 � __
2
15b. 3 � __
6
15c. 2xy2 � _____
15xy
16. 2 __ 3 � 0. _
6
17. Answers will vary. Making a free throw is not random as flipping a coin is, so Janie may be improving. However, even if her overall accuracy is still 50%, she could have a sequence of 5 successes in a row.
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120 ANSWERS TO ALL EXERCISES
LESSON 10.4
1a. Yes; the number of children will be an integer, and it is based on a random process.
1b. No; the length may be a non-integer.
1c. Yes; there will be an integer number of pieces of mail, and it is based on random processes of who sends mail when.
2a. Yes; the result of each call is independent of other calls, and you stop counting when she is successful.
2b. No; the number of cats is a discrete random variable, but you don’t stop counting when you get the first cat; it is not geometric.
2c. No; you are counting minu tes until you hear a song, but because not all songs are the same length and minutes are not equivalent to songs, you are working with two different types of variables.
3a.
x 0 1 2 3
P(x) 1 __ 8 3 __ 8 3 __ 8 1 __ 8
3b. 1.5
4a. approximately 0.068
4b. approximately 0.203
5a. 0
5b. 0
6a. Answers will vary. Theoreti cally, after 10 games Sly should get about 23 points, and Andy should get about 21.
6b. Answers will vary. Theoreti cally, it should be close to 0.41.
6c. Andy gets 5.
Sly gets 4.
15__36
21__36
6d. �0.25
6e. Answers will vary. One possible answer is 5 points for Sly if the sum of the dice is less than 8 and 7 points for Andy if the sum of the dice is greater than 7.
7a. $25
7b. 0. _ 6
7c. approximately $28.33
8a. Answers will vary.
8b. Sample answer: Assign each of the letters in the word CHAMPION a different number from 1 to 8. Randomly generate numbers between 1 and 8. Count how many digits you must gene rate until you have at least one of each number.
8c. Answers will vary.
8d. Answers will vary. Theoretically, it should be about 22 boxes.
8e. Answers will vary. The average number of boxes should be about 22.
9a. 0.2
9b. 0.83 � 0.2 = 0.1024
9c.
Successful hits Probability
0 0.2
1 0.16
2 0.128
3 0.1024
4 0.08192
5 0.065536
9d. P(n) = 0.2(0.8)n
9e. geometric
9f. P(n � 6) � 1 � � i�0
6
0.2 (0.8)i � 0.210
10a. 6. _ 8 � 7 points
10b. Answers will vary.
11a. 0.580
11b.
Number of defective radiosx
ProbabilityP(x) x � P(x)
0 0.420 0
1 0.312 0.312
2 0.173 0.346
3 0.064 0.192
4 0.031 0.124
5 0.000 0
11c. 0.974
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ANSWERS TO ALL EXERCISES 121
11d. On average, the engineer should expect to find 0.974 defective radio in a sample of 5.
12. approximately 0.047
13. 1
14. 0.4
15a.
0.04 0.16
0.33
0.07 0.03
0.07
0.13 0.17
Metal Oval
Small
15b. Calculated using the actual frequencies:
Metal
Plas.Metal
0.69 Small
Oval
Tri.
Tri.
Oval
Shape
Size
Material
Large
0.72
0.65
0.350.64
0.360.70
0.300.55
0.45
0.28
0.75
0.25
0.31
Plas.Metal
Plas.Metal
Plas.
16. n �5 ______ log � 1 _ 2 �
� 16.61
17. 44
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122 ANSWERS TO ALL EXERCISES
LESSON 10.5
1a. Yes. Different arrangements of scoops are different.
1b. No. We are not counting different arrangements separately.
1c. No. Repetition is not allowed in permutations.
1d. No. Repetition is not allowed in permutations.
2a. 12
2b. 7
2c. n � 1
2d. n
2e. 14,280
2f. n(n � 1)
2g. n � 14
3a. 210
3b. 5040
3c. (n � 2)!
_______ 2
3d. n! __ 2
4a. 24
4b. 18
4c. 256
4d. 192
5a. 10,000; 27. _
7 h
5b. 100,000; approximately 11.57 d
5c. 10
6. n � r � 6, or n � 6 and r � 5, or n � 10 and r � 3, or n � 720 and r � 1
7. r factors
8. 60
9a. 40,320
9b. 5040
9c. 0.125
9d. Sample answer: There are eight possible positions for Volume 5, all equally likely. So P(5 in rightmost slot) � 1 _ 8 � 0.125.
9e. 0.5; sample answer: there are four even-numbered books that can be in the rightmost position out of the eight books. So the probability of an even-numbered book being on the right is 4 _ 8 � 0.5.
9f. 1
9g. 40,319
9h. 1 ______ 40,320 � 0.000025
10.
11a. 100,000
11b. 1,000,000,000
11c. 17,576,000
11d. 7,200,000
12a. 1.516 � 1016
12b. 2000 min � 33.3 h, or about 1 d 9 h 20 min
12c. about 3.639 � 1017 min, or about 6.92 � 10 9 centuries
13a. 0
13b. 1 __ 4 � 0.25
13c. 2 __ 4 � 0.5
13d. It is not possible because there are no brown-eyed (B) genes in the mixture.
13e. 4 ___ 16 � 0.25
14a. 30 ___ 50 � 0.6
14b. 16 ___ 30 � 0.5 _
3
15a. �0.5
15b. You would expect to lose 0.50 point on each of the 10 tosses, or a total loss of 5 points.
16a. 1 __ 8 � 0.125
16b. 3 __ 8 � 0.375
16c. 1 __ 2 � 0.5
17a. y � �0.25x2 � 2.5x � 3.25
17b. y � �0.25(x � 5)2 � 3
17c. y � �0.25�x � 5 � 2 � __
3 � ��x � 5 � 2 �
__ 3 �
18a. 41
18b. about 808.3 in2
NNumber of
permutations of N items Time
5 120 0.00012 s
10 3,628,800 3.6288 s
12 479,001,600 � 8 min
13 6,227,020,800 � 1.7 h
15 � 1.31 � 1012 � 15 d
20 � 2.43 � 1018 � 77,100 yr
NNumber of
permutations of N items Time
5 120 0.00012 s
10 3,628,800 3.6288 s
12 479,001,600 � 8 min
13 6,227,020,800 � 1.7 h
15 � 1.31 � 1012 � 15 d
20 � 2.43 � 1018 � 77,100 yr
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ANSWERS TO ALL EXERCISES 123
LESSON 10.6
1a. 120 1b. 35
1c. 105 1d. 1
2a. 120 2b. 35
2c. 105 2d. 1
3a. 7P2 ___ 2!
� 7C2
3b. 7P3 ___ 3!
� 7C3
3c. 7P4 ___ 4!
� 7C4
3d. 7P7 ___ 7!
� 7C7
3e. nPr ___ r!
� nCr
4. Neither; they are the same.
5. n � 7 and r � 3, or n � 7 and r � 4, or n � 35 and r � 1, or n � 35 and r � 34
6. r � 6; 10! ___ 4! 6! � 10!
___ 6! 4! ; the number of 10 things taken 4 at a time is equal to the number of 10 things omitted 6 at a time.
7a. 35
7b. 20 ___ 35 � 0.571
8. Sample answer: In a true “combination” lock, the order in which the numbers are en tered would not matter. In com bination locks, the order of the numbers does matter, so they are more like permutation locks. However, in a true “permutation” lock, repeated numbers would not be allowed.
9a. 4 9b. 8 9c. 16
9d. The sum of all possible combinations of n things is 2n; 25 � 32.
10a. approximately 3.4 yr
10b. 1000 _____ 47C6
� 0.000093
11a. 6
11b. 10
11c. 36
11d. nC2 � n! ________ 2(n � 2)!
12a. 26,466,926,850 ways
12b. approximately 2.134 1019 ways
13a. 47C3 ____ 50C4
� 0.070
13b. 47C2 ____ 50C4
� 0.005
13c. 1 � 48C4 ____ 50C4
� 0.155
13d. $3.20
14a. x2 � 2xy � y2
14b. x3 � 3x2y � 3xy2 � y3
14c. x4 � 4x3y � 6x2y2 � 4xy3 � y4
15. 15 speeds
16a. 0.0194 is the probability that someone is healthy but tests positive.
16b. 0.02 is the probability that a healthy person tests positive.
16c. 0.0491 is the probability that a person tests positive.
16d. 0.395 is the probability that a person who tests positive is healthy.
17. C � 157 ____ 4 , or C � 39.25
18a. $26,376.31
18b. 20 yr 11 mo
19a. � 1 ____ �
__ 2 , 1 ____
� __
2 � , or � �
__ 2 ____ 2 , �
__ 2 ____ 2 �
19b. � 1 __ 2 , � __
3 ____ 2 �
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124 ANSWERS TO ALL EXERCISES
LESSON 10.7
1a. x 47
1b. 5,178,066,751x 37y 10
1c. 62,891,499x 7y 40
1d. 47x y 46
2a. 0.75
2b. 0.0625
2c. (0.25)n
2d. approximately 0.264
3a. 0.299
3b. 0.795, 0.496
3c. 0.203, 0.502, 0.791
3d. Both the “at most” and “at least” numbers include the case of “exactly.” For example, if “exactly” 5 birds (0.165) is subtracted from “at least” 5 birds (0.203), the result (0.038) is the same as 1 � 0.962 (“at most” 5 birds).
3e. The probability that at least 5 birds survive is 20.3%.
4. What is the probability of exactly 35 successes in 50 trials?
5. What is the probability of at least 35 successes in 50 trials?
6a. HH, HT, TH, TT
6b. HH, HT, TH, TT
6c. Both diagrams would look the same.
H HH
HT
TH
TT
T
H
T
H
Second flip/coin
First flip/coin
T
6d. 2C 0 � 1 is the number of ways of getting 0 tails,
2C 1 � 2 is the number of ways of gett ing 1 tail, and
2C2 � 1 is the number of ways of getting 2 tails.
6e. There is 1 way of getting 2 heads; there are 2 ways of getting 1 head and 1 tail; and there is 1 way of getting 2 tails.
7a. x 4 � 4x 3y � 6x 2y 2 � 4xy 3 � y 4
7b. p 5 � 5p 4q � 10p3q2 � 10p 2q 3 � 5pq 4 � q 5
7c. 8x 3 � 36x 2 � 54x � 27
7d. 81x 4 � 432x 3 � 864x 2 � 768x � 256
8a. 50C40 � p 10q 40 or 50C10 � p 10q 40
8b. the sum of terms 1 to 11, or � r�0
10
50Cr p r (1 � p)50�r
8c. P(r � 10) � 1.193 � 10�5
8d. no
9a. approximately 0.401
9b. approximately 0.940
9c. f (x) � 30Cx(0.97)30�x(0.03)x
9d. 0.940
10. 0.007
11a. 0.000257
11b. 0.446
11c. 0.983
12a. 0.049
12b. 0.079
12c. 1.88 birds, or approximately 2 birds
13. Answers will vary. This event will happen in 15.625% of trials.
14a. 0.025
14b. 0.004
14c. 0.0002
14d. 0.0288
15a.
x 1 2 3 4
Sum of the first 2 terms
2 2 2 2
Sum of all the terms 2 2.25 � 2.370 � 2.441
15b. f (10) � 2.594, f (100) � 2.705, f (1,000) � 2.717, f (10,000) � 2.718
15c. There is a long-run value of about 2.718.
16. 65,780. Sample answer: Either the group of five students selected includes the new student or it doesn’t. If the new student is included, then the other 4 are selected from the remaining 25 class members, and this can be done 25C4 � 12,650 ways. If the new student is not selected, then all 5 are selected from the 25 original members, and this can be done 25C5 � 53,130 ways. This means there are 12,650 ways that the new student is part of the group and 53,130 ways that he or she is not. This makes 12,650 � 53,130 � 65,780 ways to select 5 students.
17a. The experimental pro babilities are likely to be differ ent from 0.5 and 0.5. In this sample simulation, P(H) � 0.6 and P(T) � 0.4.
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ANSWERS TO ALL EXERCISES 125
17b. The experimental probabilities should be closer to 0.5 and 0.5, but are likely to not yet be exact. In this sample simulation, P(H) � 0.49 and P(T) � 0.51.
17c. You can model the thumbtack by defining randomPick with more “points up” to choose from. For example, randomPick(“U”,“U”,“U”,“D”, “D”) would make the experimental probability of “points up” approximately 0.6.
18. 37.44 cm2
19a. (distance, period)
x
y
9000
12,000
Distance (millions of miles)
Per
iod
(log (distance), period)
x
y
87 9
12,000
0
Log distance
Per
iod
(distance, log (period))
x
y
900
1
0
2
3
4
Distance (millions of miles)
Log
per
iod
(log (distance), log (period))
x
y
87 9
1
0
2
3
4
Log distance
Log
per
iod
(log (distance), log (period)) is the most linear of the four, so use the median-median line to find an equation to fit these points; y � 1.50x � 9.38; log (period) � 1.50 log (distance) � 9.38;
10 log (period) � 10 1.50 log (distance) �9.38;period � distance 1.50 10 �9.38
19b. 31,385; 61,566; 92,535; errors may be due to rounding. For more accurate results, the a- and b-values found from regression can be stored in variables in the calculator.
19c. period 2 � 10�18.76 distance3
20a. A � � r2, where A � area and r � radius
20b. V � l � w � h, where l � length, w � width, and h � height
20c. N � k _ d , where d � the distance from the hinge
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126 ANSWERS TO ALL EXERCISES
CHAPTER 10 REVIEW
1. Answers will vary depending upon whether you interpret the problem to imply random decimal numbers (between 0 and 10, non-inclusive) or random integers (0 to 10, inclusive). To generate random decimal numbers, you might look at a random-number table and place the decimal point after the first digit in each group of numbers. Alternatively, you could use a calculator command, such as 10*rand(numTrials) on the TI-Nspire, or 10*rand on the TI-84 Plus. To generate random integers, you might number 11 chips or slips of paper and randomly select one. Alternatively, you could use a calculator command, such as randInt(0, 10) on the TI-Nspire or the TI-84 Plus.
2a, b. 8
6
7
5
4
3
2
1
2 3 4 51 876
2c. 10 ___ 64 � 0.15625
2d. 49 ___ 64 � 0.766
3a. 0.5
3b. 17.765 units2
4a. TTTT
TTTFTTFT
TTFF
T
FT
F T
F
T
F
T
F
T
F
T
F
TFTT
TFTFTFFT
TFFFFTTT
FTTFFTFT
FTFFFFTT
FFTFFFFT
FFFF
TF
TF
TF
TF
TF
TF
TF
TF
4b. 4
4c. Because the order in which the true and false answers occur doesn’t matter, use combinations:
4C3 � 4.
4d. 2 __ 4 � 0.5
5a.
Plain0.36
P 0.62
R 0.11M 0.27
P 0.62
R 0.11M 0.27
P 0.62
R 0.11M 0.27
Veggie0.17
Chili0.47
5b. 0.0517
5c. 0.8946 5d. 0.3501
6a. See below.
6b. 37 ___ 55 � 0.6 __
72 6c. 37 ____ 122 � 0.303
6d. 18 ____ 254 � 0.071 6e. 118 ____ 372 � 0.317
7. 110.5
8.
0.16 0
0
0.04 0.42
0.20
0.06 0.12
Cats Dogs
Other
9. approximately 0.044
10a. 1
10b. x99 ____
1299
10c. 293, 930a12b9
9th grade 10th grade 11th grade 12th grade Total
Ice cream 18 37 85 114 254
Whipped cream 5 18 37 58 118
Total 23 55 122 172 372
6a. (Chapter 10 Review)
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