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 9.2, Problem 30E
The article “Flexure of Concrete Beams Reinforced with Advanced Composite Orthogrids” (J. of Aerospace Engr., 1997: 7–15) gave the accompanying data on ultimate load (kN) for two different types of beams. Sample Sample Sample Type Size
| Type | Sample Mean | Sample SD | |
| Fiberglass grid | 26 | 33.4 | 2.2 |
| Commercial | 26 | 42.8 | 4.3 |
| carbon grid |
a. Assuming that the underlying distributions are normal, calculate and interpret a 99% CI for the difference between true average load for the fiberglass beams and that for the carbon beams.
b. Does the upper limit of the interval you calculated in part (a) give a 99% upper confidence bound for the difference between the two μ’s? If not, calculate such a bound. Does it strongly suggest that true average load for the carbon beams is more than that for the fiberglass beams? Explain.
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
Two measurements are made of some quantity. For the first measurement, the average
is 74.4528, the RMS error is 6.7441, and the uncertainty of the mean is 0.9264. For the
second one, the average is 76.8415, the standard deviation is 8.3348, and the uncertainty of
the mean is 1.1448. The expected value is exactly 75.
13. Express the first measurement in public notation.
14. Is there a significant difference between the two measurements?
1
15. How does the first measurement compare with the expected value?
16. How does the second measurement compare with the expected value?
A hat contains slips of paper numbered 1 through 6. You draw two slips of paper at random from the hat,without replacing the first slip into the hat.(a) (5 points) Write out the sample space S for this experiment.(b) (5 points) Express the event E : {the sum of the numbers on the slips of paper is 4} as a subset of S.(c) (5 points) Find P(E)(d) (5 points) Let F = {the larger minus the smaller number is 0}. What is P(F )?(e) (5 points) Are E and F disjoint? Why or why not?(f) (5 points) Find P(E ∪ F )
In addition to the in-school milk supplement program, the nurse would like to increase the use of daily vitamin supplements for the children by visiting homes and educating about the merits of vitamins. She believes that currently, about 50% of families with school-age children give the children a daily megavitamin. She would like to increase this to 70%. She plans a two-group study, where one group serves as a control and the other group receives her visits. How many families should she expect to visit to have 80% power of detecting this difference? Assume that drop-out rate is 5%.
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
- A recent survey of 400 americans asked whether or not parents do too much for their young adult children. The results of the survey are shown in the data file. a) Construct the frequency and relative frequency distributions. How many respondents felt that parents do too much for their adult children? What proportion of respondents felt that parents do too little for their adult children? b) Construct a pie chart. Summarize the findingsarrow_forwardThe average number of minutes Americans commute to work is 27.7 minutes (Sterling's Best Places, April 13, 2012). The average commute time in minutes for 48 cities are as follows: Click on the datafile logo to reference the data. DATA file Albuquerque 23.3 Jacksonville 26.2 Phoenix 28.3 Atlanta 28.3 Kansas City 23.4 Pittsburgh 25.0 Austin 24.6 Las Vegas 28.4 Portland 26.4 Baltimore 32.1 Little Rock 20.1 Providence 23.6 Boston 31.7 Los Angeles 32.2 Richmond 23.4 Charlotte 25.8 Louisville 21.4 Sacramento 25.8 Chicago 38.1 Memphis 23.8 Salt Lake City 20.2 Cincinnati 24.9 Miami 30.7 San Antonio 26.1 Cleveland 26.8 Milwaukee 24.8 San Diego 24.8 Columbus 23.4 Minneapolis 23.6 San Francisco 32.6 Dallas 28.5 Nashville 25.3 San Jose 28.5 Denver 28.1 New Orleans 31.7 Seattle 27.3 Detroit 29.3 New York 43.8 St. Louis 26.8 El Paso 24.4 Oklahoma City 22.0 Tucson 24.0 Fresno 23.0 Orlando 27.1 Tulsa 20.1 Indianapolis 24.8 Philadelphia 34.2 Washington, D.C. 32.8 a. What is the mean commute time for…arrow_forwardMorningstar tracks the total return for a large number of mutual funds. The following table shows the total return and the number of funds for four categories of mutual funds. Click on the datafile logo to reference the data. DATA file Type of Fund Domestic Equity Number of Funds Total Return (%) 9191 4.65 International Equity 2621 18.15 Hybrid 1419 2900 11.36 6.75 Specialty Stock a. Using the number of funds as weights, compute the weighted average total return for these mutual funds. (to 2 decimals) % b. Is there any difficulty associated with using the "number of funds" as the weights in computing the weighted average total return in part (a)? Discuss. What else might be used for weights? The input in the box below will not be graded, but may be reviewed and considered by your instructor. c. Suppose you invested $10,000 in this group of mutual funds and diversified the investment by placing $2000 in Domestic Equity funds, $4000 in International Equity funds, $3000 in Specialty Stock…arrow_forward
- The days to maturity for a sample of five money market funds are shown here. The dollar amounts invested in the funds are provided. Days to Maturity 20 Dollar Value ($ millions) 20 12 30 7 10 5 6 15 10 Use the weighted mean to determine the mean number of days to maturity for dollars invested in these five money market funds (to 1 decimal). daysarrow_forwardc. What are the first and third quartiles? First Quartiles (to 1 decimals) Third Quartiles (to 4 decimals) × ☑ Which companies spend the most money on advertising? Business Insider maintains a list of the top-spending companies. In 2014, Procter & Gamble spent more than any other company, a whopping $5 billion. In second place was Comcast, which spent $3.08 billion (Business Insider website, December 2014). The top 12 companies and the amount each spent on advertising in billions of dollars are as follows. Click on the datafile logo to reference the data. DATA file Company Procter & Gamble Comcast Advertising ($billions) $5.00 3.08 2.91 Company American Express General Motors Advertising ($billions) $2.19 2.15 ETET AT&T Ford Verizon L'Oreal 2.56 2.44 2.34 Toyota Fiat Chrysler Walt Disney Company J.P Morgan a. What is the mean amount spent on advertising? (to 2 decimals) 2.55 b. What is the median amount spent on advertising? (to 3 decimals) 2.09 1.97 1.96 1.88arrow_forwardMartinez Auto Supplies has retail stores located in eight cities in California. The price they charge for a particular product in each city are vary because of differing competitive conditions. For instance, the price they charge for a case of a popular brand of motor oil in each city follows. Also shown are the number of cases that Martinez Auto sold last quarter in each city. City Price ($) Sales (cases) Bakersfield 34.99 501 Los Angeles 38.99 1425 Modesto 36.00 294 Oakland 33.59 882 Sacramento 40.99 715 San Diego 38.59 1088 San Francisco 39.59 1644 San Jose 37.99 819 Compute the average sales price per case for this product during the last quarter? Round your answer to two decimal places.arrow_forward
- Consider the following data and corresponding weights. xi Weight(wi) 3.2 6 2.0 3 2.5 2 5.0 8 a. Compute the weighted mean (to 2 decimals). b. Compute the sample mean of the four data values without weighting. Note the difference in the results provided by the two computations (to 3 decimals).arrow_forwardExpert only,if you don't know it don't attempt it, no Artificial intelligence or screen shot it solvingarrow_forwardFor context, the image provided below is a quesion from a Sepetember, 2024 past paper in statistical modelingarrow_forward
- For context, the images attached below (the question and the related figure) is from a january 2024 past paperarrow_forwardFor context, the image attached below is a question from a June 2024 past paper in statisical modelingarrow_forwardFor context, the images attached below are a question from a June, 2024 past paper in statistical modelingarrow_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
Correlation Vs Regression: Difference Between them with definition & Comparison Chart; Author: Key Differences;https://www.youtube.com/watch?v=Ou2QGSJVd0U;License: Standard YouTube License, CC-BY
Correlation and Regression: Concepts with Illustrative examples; Author: LEARN & APPLY : Lean and Six Sigma;https://www.youtube.com/watch?v=xTpHD5WLuoA;License: Standard YouTube License, CC-BY