Applied Statistics and Probability for Engineers

APPENDIX C 683

6-47. (a) ,

(b)s^2 7.246, s2.692

Supplemental

6-73. (a)

(b)s^2 1.86869, s1.367

6-75. (a) Sample 1: range4;

Sample 2: range 4

(b) Sample 1: s1.604;

Sample 2: s1.852

6-79. (b) ,s4.48586

CHAPTER 7

Section 7-2

7-1. Estimator 1

7-3. Estimator 2

7-5. 2.5

7-7. Estimator 3 is most efficient;

estimator 2 is the best “unbiased”

estimator.

7-11. (a) 75.427 (b) 75.1

(c)^2 2.214, 1.488

(d) 0.292 (e) 0.0385

7-13. (a) Yes (b)

7-15. (b)

7-17. (b)

(c) (d) 0.10

Section 7-3

7-31. (a) 423.33, 82.4464

Section 7-5

7-33. 0.8385

7-35. 0.43055

7-37. 0.3472

7-39. 12

7-41. 0.2313

7-43. (a) 0.5885

(b) 0.1759

7-45. 0.983

Supplemental

7-49.

7-51. 0.8664

7-53. 1 (approximately)

7-55. 0 (approximately)

X 1 X 2  N 1 5, 0.2233 2



an 1

n 2 an 1

 1

B

^2 n 2  11  22 an 1

se 1  n 1 n 2

ˆ 2

se

B

^21

n 1 

^22

n 2

1

12



x9.325

x65.083

x48.125x~ (^49) CHAPTER 8
Section 8-2
8-1. 97.93%, 99.36%, and 96.78%
8-3. (a) 1.29 (b) 1.65 (c) 2.33
8-5. 3
8-7. (a) Longer (b) No
(c) Yes
8-9. (89.471, 91.489)
8-11. (a) (74.0353, 74.0367)
(b) (74.0355, )
8-13. (a) (3232.11, 3267.89)
(b) (3226.5, 3273.5)
8-15. 267
8-17. 4
Section 8-3
8-19. t0.025,152.131, t0.05,101.812,
t0.10,201.325, t0.005,252.787,
t0.001,303.385
8-21. (a)t0.05,141.761
(b)t0.01,192.359
(c)t0.001,243.467
8-23. (1.108, )
8-25. (a) Yes (b) (16.455, 17.505)
8-27. (a) Yes (b) (8.216, 8.244)
8-29. (4.023, )
8-31. (1.093, 1.106)
Section 8-4
8-33. (^2) 0.05,1018.31,
(^2) 0.025,1527.49,
(^2) 0.01,1226.22,
(^2) 0.005,2546.93,
(^2) 0.95,2010.85,
(^2) 0.99,187.01,
(^2) 0.995,165.14
8-35. 0.00003075
^2
8-37. 7,975,727.09
^2
8-39. 0.31

0.46
8-41. 3.8
Section 8-5
8-43. 622
8-45. 666
8-47. 5759
Section 8-6
8-49. 52131.1 Xn 1 68148.3
8-51. 263.5 Xn 1 370.9
8-53. 2193.5 Xn 1 2326.5
8-55. 3.19 Xn 1 4.19
8-57. 2.56 Xn 1 3.22
8-59. 228.1 Xn 1 235.2
Section 8-7
8-61. (0.408, 2.092)
8-63. (15.14, 18.82)
8-65. (8.16, 8.30)
8-67.
8-69. (1.06, 1.14)
Supplemental
8-71. (a) 0.1 P-value 0.25
(b) 0.05 P-value 0.1
(c)P-value0.00539
8-75. (a) 40 (b) 23
8-77. 2178.51 Xn 1 2341.49
8-79. (a) Yes
(b) 0.6180.630
(c) 0.588 Xn 1 0.660
(d) (0.583, 0.665)
8-81. (a) Yes
(b) 2.2704.260
(c)1.297 Xn 1 7.827
(d) (3.113, 10.363)
8-83. (a) 0.0021 p 0.0088
(b) Yes
8-85. (a) 0.210 p 0.274
(b) 0.204 p 0.280
CHAPTER 9
Section 9-1
9-1. (a) Yes (b) No (c) No
(d) No (e) No
9-3. (a) 0 (b) 0.02275
9-5. 11.5875
9-7. (a) 0.09296 (b) 0.04648
(c) 0.00005
9-9. (a) RejectH 0 (b) 0.00889
9-11. (a) 182.9 (b) 0.00776
9-13. (a) 0.0164 (b) 0.21186
9-17. (a) 0.08535 (b) 0
9-19. (a) 0.29372 (b) 0.25721
Section 9-2
9-21. (a)z 0 0.36, do not reject H 0
(b)P-value0.71884 (c) 5
(d) 0.68054 (e) (87.85, 93.11)
9-23. (a)z 0 1.69, do not reject H 0
(b) 0.091028 (c) 0 (d) 1
9-25. (a)z 0 14.43, reject H 0
(b) 0 (c) (3232.11, 3267.89)
9-27. (a)z 0 1.55, do not reject H 0
(b) 0.02938 (c) 1
(d) (99.888, )
9-29. (a)z 0 1.77, reject H 0 (b) 1
(c) 35 (d) (4.003, )
1 3.91,  2
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