Appendix A-1: Solutions to Review Exercises (Ch 3-13)

Chapter 3

1. c. parameter

2. a. population

3. b. statistic

4. d. sample

5. e. variable

6. quantitative continuous

7.

2.27
3.04
–1, 4, 4

8. Answers will vary.

Chapter 4

9. c. (0.80)(0.30)

10. b. No, and they are not mutually exclusive either.

11. a. all employed adult women

12. 0.5773

13. 0.0522

14. b. The middle fifty percent of the members lost from 2 to 8.5 lbs.

15. c. All of the data have the same value.

16. c. The lowest data value is the median.

17. 0.279

18. b. No, I expect to come out behind in money.

19. X = the number of patients calling in claiming to have the flu, who actually have the flu.

X = 0, 1, 2, …25

20. B(25, 0.04)

21. 0.0165

22. 1

23. c. quantitative discrete

24. all words used by Tom Clancy in his novels

Chapter 5

25.

24%
27%

26. qualitative

27. 0.36

28. 0.7636

29.

No
No

30. B(10, 0.76)

31. 0.9330

32.

X = the number of questions posted to the statistics listserv per day.
X = 0, 1, 2,…
X ~ P(2)
0

33. $150

34. Matt

35.

false
true
false
false

36. 16

37. first quartile: 2

second quartile: 2

third quartile: 3

38. 0.5

39. 715

40. 215

Chapter 6

41.

true
true
False – the median and the mean are the same for this symmetric distribution.
true

42.

8
8
P(x < k) = 0.65 = (k – 3)(110). k = 9.5

43.

False – 34 of the data are at most five.
True – each quartile has 25% of the data.
False – that is unknown.
False – 50% of the data are four or less.

44. d. G and H are independent events.

45.

False – J and K are independent so they are not mutually exclusive which would imply dependency (meaning P(J AND K) is not 0).
False – see answer c.
True – P(J OR K) = P(J) + P(K) – P(J AND K) = P(J) + P(K) – P(J)P(K) = 0.3 + 0.6 – (0.3)(0.6) = 0.72. Note the P(J AND K) = P(J)P(K) because J and K are independent.
False – J and K are independent so P(J) = P(J|K)

46. a. P(5)

Chapter 7

47. a. U(0, 4)

48. b. 2 hour

49. a. 14

50.

0.7165
4.16
0

51. c. 5 years

52. c. exponential

53. 0.63

54. B(14, 0.20)

55. B(14, 0.20)

Chapter 8

56. c. the mean amount of weight lost by 15 people on the special weight loss diet.

57. 0.9951

58. 12.99

59. c. 12

60. b. 0.60

61. c. N(60, 5.477)

62. 0.9990

63. a. eight days

64. c. 0.7500

65. a. 80%

66. b. 35%

67. b. no

68. b. quantitative continuous

69. c. 150

70. d. 0.06

71. c. 0.44

72. b. 0

Chapter 9

73. d. Matt is shorter than the average 14 year old boy.

74. Answers will vary.

75.

x Relative Frequency Cumulative Relative Frequency
1 0.3 0.3
2 0.2 0.2
4 0.4 0.4
5 0.1 0.1

76.

2.8
1.48
90%

77. M = 3; Q1 = 1; Q3 = 4

78. 1 and 4

79. d. 870

80. c. 4070

81. a. 919

82. b. false

83. b. false

84. b. false

85.

X = the number of pies Lee bakes every day.
P(20)
0.1122

86. CI: (5.25, 8.48)

87.

uniform
exponential
normal

Chapter 10

88. 77100

89. 1242

90.

false
false
true
false

91. N(180, 16.43)

92. a. The distribution for X⎯⎯⎯ is still uniform with the same mean and standard deviation as the distribution for X.

93. c. The distribution for ∑X is normal with a larger mean and a larger standard deviation than the distribution for X.

94. N(2, 0.2516√)

95. Answers will vary.

96. 0.5000

97. 7.6

98. 5

99. 0.9431

Chapter 11

100. 7.5

101. 0.0122

102. N(7, 0.63)

103. 0.9911

104. b. Exponential

105.

true
false
false

106. Answers will vary.

107. Student’s t with df = 15

108. (560.07, 719.93)

109. quantitative continuous data

110. quantitative discrete data

111.

X = the number of patients with a shotgun wound the emergency room gets per 28 days
P(4)
0.0183

112. greater than

113. No; P(x = 8) = 0.0348

114. You will lose $5.

115. Becca

116. 14

117. Sample mean = 3.2

Sample standard deviation = 1.85

Median = 3

Q1 = 2

Q3 = 5

IQR = 3

118. d. z = –1.19

e. 0.1171

f. Do not reject the null hypothesis.

119. We conclude that the patient does have the HIV virus when, in fact, the patient does not.

120. c. z = 2.21; p = 0.0136

d. Reject the null hypothesis.

e. We conclude that the proportion of Californian professionals that wear jeans to work is greater than the proportion of non-Californian professionals when, in fact, it is not greater.

f. We cannot conclude that the proportion of Californian professionals that wear jeans to work is greater than the proportion of non-Californian professionals when, in fact, it is greater.

121. c. dependent means

122. t5

Chapter 12

123. (0.0424, 0.0770)

124. 2,401

125. Check student’s solution.

126. 0.6321

127. $360

128. N(72, 725√)

Chapter 13

129. 0.02

130. 0.40

131. 100140

132. 1060

133. p-value = 0; Reject the null hypothesis; conclude that they are dependent events

134. 8.4

135. B(14, 0.60)

136. d. Binomial

137. 0.3669

138. p-value = 0.0006; reject the null hypothesis; conclude that the averages are not equal

139. p-value = 0; reject the null hypothesis; conclude that the proportion of males is higher

140. Minimize α and β

141.

No
Yes, P(M AND 30+) = 0

142. 1238

143. No; p-value = 0

144. a. uniform

References

Data from the San Jose Mercury News.

Baran, Daya. “20 Percent of Americans Have Never Used Email.” Webguild.org, 2010. Available online at: http://www.webguild.org/20080519/20-percent-of-americans-have-never-used-email (accessed October 17, 2013).

Data from Parade Magazine.