Student Solutions Manual for Devore's Probability and Statistics for Engineering and the Sciences, 9th
9th Edition
ISBN: 9798214004020
Author: Jay L. Devore
Publisher: Cengage Learning US
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Textbook Question
Chapter 9.4, Problem 57E
Two different types of alloy, A and B, have been used to manufacture experimental specimens of a small tension link to be used in a certain engineering application. The ultimate strength (ksi) of each specimen was determined, and the results are summarized in the accompanying frequency distribution
| A | B | |
| 26- <30 | 6 | 4 |
| 30- <34 | 12 | 9 |
| 34- <38 | 15 | 19 |
| 38 - <42 | 7 | 10 |
| m = 40 | m = 42 |
Compute a 95% CI for the difference between the true proportions of all specimens of alloys A and B that have an ultimate strength of at least 34 ksi.
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The data in the table below consist of measurements y₁, y2, y3, and yn of the ramus bone at four
different ages on each of 20 boys.
1. Find y.
2. Find Sn
3. Find R
Ramus Bone Length at Four Different Ages for 20 Boys.
Age
Individual
1
23
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
8 yr (yi)
47.8
46.4
46.3
45.1
47.6
52.5
51.2
49.8
48.1
45
51.2
48.5
52.1
48.2
49.6
50.7
47.2
53.3
46.2
46.3
8½ yr
(Y2)
48.8
47.3
46.8
45.3
48.5
53.2
53
50
50.8
47
51.4
49.2
52.8
48.9
50.4
51.7
47.7
54.6
47.5
47.6
9 yr
(Y3)
49
47.7
47.8
46.1
48.9
53.3
54.3
50.3
52.3
47.3
51.6
53
53.7
49.3
51.2
52.7
48.4
55.1
48.1
51.3
9½ yr
(Y4)
49.7
48.4
48.5
47,2
49.3
53.7
54.5
52.7
54.4
48.3
51.9
55.5
55
49.8
51.8
53.3
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55.3
48.4
51.8
An artide in the ACI Materials Joumal (vol. 4, 1987, pp. 213-216) describes several experiments investigating the rodding of concrete to
remove trapped ar. Anchxinch cylinder was used, and the number of times this rod was used is the design variable. The resulting
compresive strength of the concrete specimen is the response. The data are shown n the followng table.
Compressive Strength (psi)
Rodding Level
Observations
10
1530
1530
1440
15
1610
1650
1500
20
1560
1730
1530
25
1500
1490
1510
Calculate the test statistic fo
Input answer up to 2 decimal places.
TestStatistict- Blank 1
Blank 1
Add your answer
Q.1
Two samples A and B were taken from a large concrete mix and tested for the
compressive strength of concrete (in MPa), find the mean, median and mode of each
of the two samples. The results of tested specimens from each sample were as follows:
Compressive Strength
(МPа)
15
18
21
24
27
30
Sample A
Frequency
2
4
1
Sample B
Frequency
3
1,
3.
Chapter 9 Solutions
Student Solutions Manual for Devore's Probability and Statistics for Engineering and the Sciences, 9th
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