Appendices

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

Barbara Illowsky & OpenStax et al.

## 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. 