Probability and Statistics for Engineering and the Sciences
9th Edition
ISBN: 9781305251809
Author: Jay L. Devore
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
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.
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
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
49.5
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
Probability and Statistics for Engineering and the Sciences
Ch. 9.1 - An article in the November 1983 Consumer Reports...Ch. 9.1 - The National Health Statistics Reports dated Oct....Ch. 9.1 - Pilates is a popular set of exercises for the...Ch. 9.1 - Reliance on solid biomass fuel for cooking and...Ch. 9.1 - Persons having Reynauds syndrome are apt to suffer...Ch. 9.1 - An experiment to compare the tension bond strength...Ch. 9.1 - Is there any systematic tendency for part-time...Ch. 9.1 - Tensile-strength tests were carried out on two...Ch. 9.1 - The article Evaluation of a Ventilation Strategy...Ch. 9.1 - An experiment was performed to compare the...
Ch. 9.1 - The level of lead in the blood was determined for...Ch. 9.1 - The accompanying summary data on total cholesterol...Ch. 9.1 - A mechanical engineer wishes to compare strength...Ch. 9.1 - The level of monoamine oxidase (MAO) activity in...Ch. 9.1 - Prob. 15ECh. 9.1 - Prob. 16ECh. 9.2 - Determine the number of degrees of freedom for the...Ch. 9.2 - Which way of dispensing champagne, the traditional...Ch. 9.2 - Suppose 1 and 2 are true mean stopping distances...Ch. 9.2 - Use the data of Exercise 19 to calculate a 95% CI...Ch. 9.2 - Quantitative noninvasive techniques are needed for...Ch. 9.2 - According to the article Modeling and Predicting...Ch. 9.2 - Fusible interlinings are being used with...Ch. 9.2 - Damage to grapes from bird predation is a serious...Ch. 9.2 - The accompanying data consists of prices () for...Ch. 9.2 - The article The Influence of Corrosion Inhibitor...Ch. 9.2 - Anorexia Nervosa (AN) is a psychiatric condition...Ch. 9.2 - As the population ages, there is increasing...Ch. 9.2 - The article Effect of Internal Gas Pressure on the...Ch. 9.2 - The article Flexure of Concrete Beams Reinforced...Ch. 9.2 - Refer to Exercise 33 in Section 7.3. The cited...Ch. 9.2 - The degenerative disease osteoarthritis most...Ch. 9.2 - The article The Effects of a Low-Fat, Plant-Based...Ch. 9.2 - Consider the pooled t variable T=(XY)(12)sp1m+1n...Ch. 9.2 - Prob. 35ECh. 9.3 - Consider the accompanying data on breaking load...Ch. 9.3 - Prob. 37ECh. 9.3 - Adding computerized medical images to a database...Ch. 9.3 - Scientists and engineers frequently wish to...Ch. 9.3 - Lactation promotes a temporary loss of bone mass...Ch. 9.3 - Antipsychotic drugs are widely prescribed for...Ch. 9.3 - Many freeways have service (or logo) signs that...Ch. 9.3 - Cushings disease is characterized by muscular...Ch. 9.3 - Prob. 44ECh. 9.3 - Torsion during hip external rotation (ER) and...Ch. 9.3 - Example 7.11 gave data on the modulus of...Ch. 9.3 - The article Slender High-Strength RC Columns Under...Ch. 9.3 - Prob. 48ECh. 9.4 - Consider the following two questions designed to...Ch. 9.4 - Recent incidents of food contamination have caused...Ch. 9.4 - It is well known that a placebo, a fake medication...Ch. 9.4 - Do teachers find their work rewarding and...Ch. 9.4 - Olestra is a fat substitute approved by the FDA...Ch. 9.4 - Teen Court is a juvenile diversion program...Ch. 9.4 - In medical investigations, the ratio = p1/p2 is...Ch. 9.4 - Sometimes experiments involving success or failure...Ch. 9.4 - Two different types of alloy, A and B, have been...Ch. 9.4 - Prob. 58ECh. 9.5 - Obtain or compute the following quantities: a....Ch. 9.5 - Give as much information as you can about the...Ch. 9.5 - Prob. 61ECh. 9.5 - Prob. 62ECh. 9.5 - Toxaphene is an insecticide that has been...Ch. 9.5 - The following observations are on time (h) for a...Ch. 9.5 - The article Enhancement of Compressive Properties...Ch. 9.5 - Prob. 66ECh. 9 - The accompanying summary data on compression...Ch. 9 - The article Supervised Exercise Versus Non-...Ch. 9 - Is the response rate for questionnaires affected...Ch. 9 - Shoveling is not exactly a high-tech activity, but...Ch. 9 - The article Quantitative MRI and Electrophysiology...Ch. 9 - The following summary data on bending strength...Ch. 9 - Prob. 73SECh. 9 - The derailment of a freight train due to the...Ch. 9 - Prob. 75SECh. 9 - Prob. 76SECh. 9 - Information about hand posture and forces...Ch. 9 - Prob. 78SECh. 9 - The article The Accuracy of Stated Energy Contents...Ch. 9 - Arsenic is a known carcinogen and poison. The...Ch. 9 - Prob. 81SECh. 9 - Acrylic bone cement is commonly used in total...Ch. 9 - In an experiment to compare bearing strengths of...Ch. 9 - Prob. 84SECh. 9 - An experimenter wishes to obtain a CI for the...Ch. 9 - Prob. 86SECh. 9 - Prob. 87SECh. 9 - The paper Quantitative Assessment of Glenohumeral...Ch. 9 - Prob. 89SECh. 9 - Prob. 90SECh. 9 - Prob. 91SECh. 9 - Prob. 92SECh. 9 - The article Evaluating Variability in Filling...Ch. 9 - Prob. 94SECh. 9 - Prob. 95SE
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.Similar questions
- Values of modulus of elasticity (MOE, the ratio of stress, i.e., force per unit area, to strain, i.e., deformation per unit length, in GPa) and flexural strength (a measure of the ability to resist failure in bending, in MPa) were determined for a sample of concrete beams of a certain type, resulting in the following data: MOE 29.7 33.1 33.6 35.2 35.4 36.2 36.2 36.3 37.4 37.8 Strength 5.8 7.1 7.2 6.2 8.0 6.9 7.1 7.7 6.7 6.4 МОЕ 38.6 38.7 39.7 40.9 42.7 42.7 43.6 45.7 45.9 46.8 Strength 7.1 6.4 8.0 8.9 8.3 8.8 7.9 9.6 7.3 7.6 МОЕ 47.9 49.2 51.6 62.7 69.7 79.6 80.1 Strength 9.8 7.7 7.8 11.5 11.4 11.9 10.6 Fitting the simple linear regression model to the n = 27 observations on x = modulus of elasticity and y = flexural strength given in the data above resulted in ý = 7.589, s, = 0.180 when x = 40 and ý = 9.749, s, = 0.255 for x = 60. The simple linear regression model also resulted in a value of s = 0.8718. (a) Explain why s, is larger when x = 60 than when x = 40. O The closer x is to…arrow_forwardValues of modulus of elasticity (MOE, the ratio of stress, i.e., force per unit area, to strain, i.e., deformation per unit length, in GPa) and flexural strength (a measure of the ability to resist failure in bending, in MPa) were determined for a sample of concrete beams of a certain type, resulting in the following data: MOE 29.7 33.1 33.6 35.2 35.4 36.2 36.2 36.3 37.4 37.8 Strength 5.8 7.1 7.2 6.2 8.0 6.9 7.1 7.7 6.7 6.4 MOE 38.6 38.7 39.7 40.9 42.7 42.7 43.6 45.7 45.9 46.8 Strength 7.1 6.4 8.0 8.9 8.3 8.8 7.9 9.6 7.3 7.6 MOE 47.9 49.2 51.6 62.7 69.7 79.6 80.1 Strength 9.8 7.7 7.8 11.5 11.4 11.9 10.6 Fitting the simple linear regression model to then = 27 observations on x = modulus of elasticity and y = flexural strength given in the data above resulted in ý = 7.589, s, = 0.180 when x = 40 and ý = 9.749, s, = 0.255 for x = 60. The simple linear regression model also resulted in a value of s = 0.8718.arrow_forwardA study was conducted in the tidal flat at Polka Point, North Stradbroke Island to examine the distribution of the animals that live with the seagrass Sargassum at different distances from the shoreline. Samples of Sargassum were taken at 5, 10, 15 m from the shore and these were examined for amphipods and isopods. The observations are recorded below. Is the distribution of each of the organisms with regards to the shore the same at all three distances? Use the data below to test the hypothesis at the p < 0.05 level. Clearly state the hypotheses and interpret the results. (Note: Find chi-square for each individual column (amphipods and isopods, not the two together) Distance Amphipods Isopods 5 2 7 10 31 14 15 45 22arrow_forward
- An alloy manufacturer is investigating if they can improve the strength of one of their alloysby producing it at a lower temperature. To investigate that, they produce the alloy at twodifferent temperatures (high and low) and then measure the breaking strength of randomsamples of specimens from each. The following table represents the strength of the randomsamples at the higher and lower temperature, in units of 0.001-inch deflection. Temp. Strength (0.001 inch)High 87 64 66 85 76 49 97 73 75 77 69 68 89 27 58 84Low 88 82 81 85 79 80 88 78 77 85 79 76 Do the results support the hypothesis that lowering the production temperature can improve thestrength of the alloy, with 95% confidence? (Hint: Don’t forget investigating variances. Use 98% confidence for that.)arrow_forwardThe Turbine Oil Oxidation Test (TOST) and the Rotating Bomb Oxidation Test (RBOT) are two different procedures for evaluating the oxidation stability of steam turbine oils. An article reported the accompanying observations on x = TOST time (hr) and y = RBOT time (min) for 12 oil specimens. TOST 4200 3600 3750 3650 4050 2770 RBOT 370 345 375 315 350 205 TOST 4870 4525 3450 2700 3750 3325 RBOT 400 380 285 220 345 290 (a) Calculate the value of the sample correlation coefficient. (Round your answer to four decimal places.) r = Carry out a test of hypotheses to decide whether RBOT Time and TOST time are linearly related. (Use ? = 0.05.) Calculate the test statistic and determine the P-value. (Round your test statistic to two decimal places and your P-value to three decimal places.) t = P-value =arrow_forwardStructural Engineers in an iron manufacturing company describe the results of deformation on the natural frequency of alloys made from composite material. Five such delaminated alloys were subjected to loads, and the resulting frequencies (in hertz) were as follows: 230.66, 233.05, 232.58, 229.48, 232.58 Compute a 90% prediction interval on the diameter of the natural frequency of the next beam of this type that will be tested. O a. The 90% prediction interval is wider than the 90% confidence interval on the population mean O b. None of the above O c. 228.1 < Xn+1<235.2 O d. 230.2 <µ < 233.1arrow_forward
- In a Nicd battery, a fully charged cell is composed of nickelic hydroxide. Nickel is an element that has multiple oxidation states. Assume the following proportions of the states: Nickel Proportions Charge Found 0.15 +2 0.35 +3 0.33 +4 0.17 Determine the mean and variance of the nickel charge. a. μ= Ε(Χ) = 2.37 o2 = V (X) = 1.47 Ο b. μ= Ε(Χ) 2.29 o = 1.53 |c. None among the choices O d. u = E(X) = 2.29 o² = V (X) = 1.53arrow_forwardThe Turbine Oil Oxidation Test (TOST) and the Rotating Bomb Oxidation Test (RBOT) are two different procedures for evaluating the oxidation stability of steam turbine oils. An article reported the accompanying observations on x = TOST time (hr) and y = RBOT time (min) for 12 oil specimens. TOST 4200 3600 3750 3675 4050 2745 RBOT 370 335 375 310 350 200 TOST 4870 4475 3450 2675 3750 3275 RBOT 400 370 285 230 345 290arrow_forwardThe Turbine Oil Oxidation Test (TOST) and the Rotating Bomb Oxidation Test (RBOT) are two different procedures for evaluating the oxidation stability of steam turbine oils. An article reported the accompanying observations on x = TOST time (hr) and y = RBOT time (min) for 12 oil specimens. TOST 4200 3600 3750 3675 4050 2745 RBOT 370 335 375 310 350 200 TOST 4870 4475 3450 2675 3750 3275 RBOT 400 370 285 230 345 290 (a) Calculate the value of the sample correlation coefficient. (Round your answer to four decimal places.) r3= Interpret the value of the sample correlation coefficient. O The value of rindicates that there is a weak, positive linear relationship between TOST and RBOT. O The value of r indicates that there is a strong, negative linear relationship between TOST and RBOT. O The value of r indicates that there is a weak, negative linear relationship between TOST and RBOT. O The value of rindicates that there is a strong, positive linear relationship between TOST and RBOT. (b)…arrow_forward
- A purchasing agent obtained 60 watt bulbs from two companies. He has the samples tested in his laboratory for the length of the life with the following results: Length of Life (in hours) 1700 and under 1900 1900 and under 2100 2100 and under 2300 2300 and under 2500 2500 and under 2700 Соmpany A Соmpany B 12 3 14 30 20 17 8 6 2 a. Which Company's bulb do you think are better in terms of average life? b. If price of both types are the same, which company's bulbs would you buy and why? ( Coefficient of variation is Mean /Standard deviation **100)arrow_forwardassume that the data was obtained from two indepen-dent samples. That is, 28 subjects were enrolled into the study, and half were randomly assignedto the corn flakes diet, and half to the oat bran diet. After two weeks the LDL cholesterol level ofeach individual was recorded. LDL (mmol/l)Subject Corn Flakes Oat Bran1 4.61 3.842 6.42 5.573 5.40 5.854 4.54 4.805 3.98 3.686 3.82 2.967 5.01 4.418 4.34 3.729 3.80 3.4910 4.56 3.8411 5.35 5.2612 3.89 3.7313 2.25 1.8414 4.24 4.14 Questions; a) What are the appropriate null and alternative hypotheses for a two-sided test?(b) Conduct the test at the 0.05 level of significance. What is the p-value?(c) Construct a 95% confidence interval.arrow_forwardThe Turbine Oil Oxidation Test (TOST) and the Rotating Bomb Oxidation Test (RBOT) are two different procedures for evaluating the oxidation stability of steam turbine oils. An article reported the accompanying observations on x = TOST time (hr) and y = RBOT time (min) for 12 oil specimens. TOST 4200 3600 3750 3650 4050 2795 RBOT 370 340 375 310 350 205 TOST 4870 4500 3450 2700 3750 3275 RBOT 400 375 285 225 345 290 (a) Calculate the value of the sample correlation coefficient. (Round your answer to four decimal places.)arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
The Shape of Data: Distributions: Crash Course Statistics #7; Author: CrashCourse;https://www.youtube.com/watch?v=bPFNxD3Yg6U;License: Standard YouTube License, CC-BY
Shape, Center, and Spread - Module 20.2 (Part 1); Author: Mrmathblog;https://www.youtube.com/watch?v=COaid7O_Gag;License: Standard YouTube License, CC-BY
Shape, Center and Spread; Author: Emily Murdock;https://www.youtube.com/watch?v=_YyW0DSCzpM;License: Standard Youtube License