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
thumb_up100%
Chapter 8.3, Problem 40E
Polymer composite materials have gained popularity because they have high strength to weight ratios and are relatively easy and inexpensive to manufacture. However, their nondegradable nature has prompted development of environmentally friendly composites using natural materials. The article “Properties of Waste Silk Short Fiber/Cellulose Green Composite Films” (J. of Composite Materials, 2012: 123–127) reported that for a sample of 10 specimens with 2% fiber content, the sample mean tensile strength (MPa) was 51.3 and the sample standard deviation was 1.2. Suppose the true average strength for 0% fibers (pure cellulose) is known to be 48 MPa. Does the data provide compelling evidence for concluding that true average strength for the WSF/cellulose composite exceeds this value?
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
Lactation promotes a temporary loss of bone mass to provide adequate amounts of calcium for milk production. The paper “Bone Mass Is Recovered from Lactation to Postweaning in Adolescent Mothers with Low Calcium Intakes” (Amer. J. of Clinical Nutr., 2004: 1322–1326) gave the following data on total body bone mineral content (TBBMC) (g) for a sample both during lactation (L) and in the postweaning period (P). SubjectL 1928 2549 2825 1924 1628 2175 2114 2621 1843 2541P 2126 2885 2895 1942 1750 2184 2164 2626 2006 2627
Does the data suggest that true average total body bone mineral content during postweaning exceeds that during lactation by more than 25 g? State and test the appropriate hypotheses using a significance level of .05.
The article “Dynamics of Insulin Action in Hypertension: Assessment from Minimal ModelInterpretation of Intravenous Glucose Tolerance Test Data” (R. Burattini, M. Morettini, etal., Med Biol Eng Comput, 2011:831–841) compared levels of an insulin sensitivity index SIin patients with high blood pressure and patients with normal blood pressure. Ten patientswith high blood pressure had a mean value of 3.4 with a standard deviation of 0.6, and eightpatients with normal blood pressure had a mean value of 7.9 with a standard deviation of0.6. Units are 10−5 · min−1 · pmol−1. Find a 98% confidence interval for the difference inmean levels between those with high blood pressure and those with normal blood pressure.
The article “Structural Performance of Rounded Dovetail Connections Under Different Loading Conditions” (T. Tannert, H. Prion, and F. Lam, Can J Civ Eng, 2007:1600–1605) describes a study of the deformation properties of dovetail joints. In one experiment, 10 rounded dovetail connections and 10 double rounded dovetail connections were loaded until failure. The rounded connections had an average load at failure of 8.27 kN with a standard deviation of 0.62 kN. The double-rounded connections had an average load at failure of 6.11 kN with a standard deviation of 1.31 kN. Can you conclude that the mean load at failure is greater for rounded connections than for double-rounded connections?
Chapter 8 Solutions
Probability and Statistics for Engineering and the Sciences
Ch. 8.1 - For each of the following assertions, state...Ch. 8.1 - For the following pairs of assertions, indicate...Ch. 8.1 - For which of the given P-values would the null...Ch. 8.1 - Pairs of P-values and significance levels, , are...Ch. 8.1 - To determine whether the pipe welds in a nuclear...Ch. 8.1 - Let denote the true average radioactivity level...Ch. 8.1 - Before agreeing to purchase a large order of...Ch. 8.1 - Many older homes have electrical systems that use...Ch. 8.1 - Water samples are taken from water used for...Ch. 8.1 - A regular type of laminate is currently being used...
Ch. 8.1 - Prob. 11ECh. 8.1 - A mixture of pulverized fuel ash and Portland...Ch. 8.1 - The calibration of a scale is to be checked by...Ch. 8.1 - A new design for the braking system on a certain...Ch. 8.2 - Let denote the true average reaction time to a...Ch. 8.2 - Newly purchased tires of a particular type are...Ch. 8.2 - Answer the following questions for the tire...Ch. 8.2 - Reconsider the paint-drying situation of Example...Ch. 8.2 - The melting point of each of 16 samples of a...Ch. 8.2 - Lightbulbs of a certain type are advertised as...Ch. 8.2 - The desired percentage of SiO2 in a certain type...Ch. 8.2 - To obtain information on the corrosion-resistance...Ch. 8.2 - Automatic identification of the boundaries of...Ch. 8.2 - Unlike most packaged food products, alcohol...Ch. 8.2 - Body armor provides critical protection for law...Ch. 8.2 - Prob. 26ECh. 8.2 - Show that for any 0, when the population...Ch. 8.2 - For a fixed alternative value , show that () 0 as...Ch. 8.3 - The true average diameter of ball bearings of a...Ch. 8.3 - A sample of n sludge specimens is selected and the...Ch. 8.3 - The paint used to make lines on roads must reflect...Ch. 8.3 - The relative conductivity of a semiconductor...Ch. 8.3 - The article The Foremans View of Quality Control...Ch. 8.3 - The following observations are on stopping...Ch. 8.3 - The article Uncertainty Estimation in Railway...Ch. 8.3 - Have you ever been frustrated because you could...Ch. 8.3 - The accompanying data on cube compressive strength...Ch. 8.3 - A random sample of soil specimens was obtained,...Ch. 8.3 - Reconsider the accompanying sample data on expense...Ch. 8.3 - Polymer composite materials have gained popularity...Ch. 8.3 - A spectrophotometer used for measuring CO...Ch. 8.4 - Prob. 42ECh. 8.4 - Prob. 43ECh. 8.4 - A manufacturer of nickel-hydrogen batteries...Ch. 8.4 - A random sample of 150 recent donations at a...Ch. 8.4 - It is known that roughly 2/3 of all human beings...Ch. 8.4 - The article Effects of Bottle Closure Type on...Ch. 8.4 - With domestic sources of building supplies running...Ch. 8.4 - A plan for an executive travelers club has been...Ch. 8.4 - Each of a group of 20 intermediate tennis players...Ch. 8.4 - A manufacturer of plumbing fixtures has developed...Ch. 8.4 - In a sample of 171 students at an Australian...Ch. 8.5 - Reconsider the paint-drying problem discussed in...Ch. 8.5 - Consider the large-sample level .01 test in...Ch. 8.5 - Consider carrying out m tests of hypotheses based...Ch. 8.5 - Prob. 56ECh. 8 - A sample of 50 lenses used in eyeglasses yields a...Ch. 8 - In Exercise 57, suppose the experimenter had...Ch. 8 - It is specified that a certain type of iron should...Ch. 8 - One method for straightening wire before coiling...Ch. 8 - Contamination of mine soils in China is a serious...Ch. 8 - The article Orchard Floor Management Utilizing...Ch. 8 - The article Caffeine Knowledge, Attitudes, and...Ch. 8 - Annual holdings turnover for a mutual fund is the...Ch. 8 - The true average breaking strength of ceramic...Ch. 8 - Prob. 66SECh. 8 - The incidence of a certain type of chromosome...Ch. 8 - Prob. 68SECh. 8 - Prob. 69SECh. 8 - The Dec. 30, 2009. the New York Times reported...Ch. 8 - When X1, X2,, Xn are independent Poisson...Ch. 8 - An article in the Nov. 11, 2005, issue of the San...Ch. 8 - Prob. 73SECh. 8 - The article Analysis of Reserve and Regular...Ch. 8 - Prob. 75SECh. 8 - Chapter 7 presented a CI for the variance 2 of a...Ch. 8 - Prob. 77SECh. 8 - When the population distribution is normal and n...Ch. 8 - Let X1, X2, Xn be a random sample from an...Ch. 8 - Because of variability in the manufacturing...
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
- The lower quartile (Q1) height for JV players is the same as the ______ for Varsity players.arrow_forwardIn experiments to determine the effectiveness of drugs such as anti-fungal ointments that are applied to the skin, the concentration of the drug in a patient’s skin must be measured. The article “Determining Bioequivalence of Topical Dermatological Drug Products by Tape- Stripping” (W. Navidi, A. Hutchinson, et al., Journal of Pharmacokinetics and Pharmacodynamics, 2008:213–220) describes an improved method of measuring that is designed to ensure that all the drug in the skin is recovered. Assume that in an experiment using the old method, the mean amount of drug recovered from a sample of 49 patients was 105 ng with a standard deviation of 20 ng, and that in an experiment using the new method the mean amount of drug recovered in a sample of 35 patients was 117 ng with a standard deviation of 15 ng. Find a 98% confidence interval for the difference in the mean amounts recovered between the two methods.arrow_forwardThe National Transportation Safety Board wants to look at the safety of three different sizes of cars. Using the data below, determine the whether the mean pressure applied to the driver`s head during a crash is equal for each type of car at alpha = 0.01 Compact cars Midsize cars Full-size Cars 643 469 484 655 427 456 702 525 402 a) Ho: Ha : b) Decision c) Conclusionarrow_forward
- An article in Knee Surgery, Sports Traumatology, Arthroscopy (2005, Vol. 13, pp. 273-279) considered arthroscopic meniscal repair with an absorbable screw. Results showed that for tears greater than 25 millimeters, 14 of 18 (78%) repairs were successful, but for shorter tears, 22 of 30 (73%) repairs were successful. A doctor would like to know if there is evidence that the success rate is greater for longer tears. The P-value for the test H0: p1 = p2 versus H1: p1 > p2 is closest to:arrow_forwardStressed-Out Bus Drivers. Previous studies have shown that urban bus drivers have an extremely stressful job, and a large proportion of drivers retire prematurely with disabilities due to occupational stress. In the paper, “Hassles on the Job: A Study of a Job Intervention With Urban Bus Drivers” (Journal of Organizational Behavior, Vol. 20, pp. 199–208), G. Evans et al. examined the effects of an intervention program to improve the conditions of urban bus drivers.Amongother variables, the researchers monitored diastolic blood pressure of bus drivers in downtown Stockholm, Sweden. The data, in millimeters of mercury (mm Hg), on the WeissStats site are based on the blood pressures obtained prior to intervention for the 41 bus drivers in the study. Use the technology of your choice to do the following. a. Obtain a normal probability plot, boxplot, histogram, and stemand-leaf diagram of the data. b. Based on your results from part (a), can you reasonably apply the one-mean t-test to the…arrow_forwardDetermine the kurtosis if the data given is a sample.arrow_forward
- Tardigrades, or water bears, are a type of micro-animal famous for their resilience. In examining the effects of radiation on organisms, an expert claimed that the amount of gamma radiation needed to sterilize a colony of tardigrades no longer has a mean of 900 Gy (grays). (For comparison, humans cannot withstand more than 10 Gy .) A study was conducted on a sample of 27 randomly selected tardigrade colonies, finding that the amount of gamma radiation needed to sterilize a colony had a sample mean of 907 Gy , with a sample standard deviation of 17 Gy . Assume that the population of amounts of gamma radiation needed to sterilize a colony of tardigrades is approximately normally distributed. Complete the parts below to perform a hypothesis test to see if there is enough evidence, at the 0.05 level of significance, to support the claim that μ , the mean amount of gamma radiation needed to sterilize a colony of tardigrades, is not equal to 900…arrow_forwardTardigrades, or water bears, are a type of micro-animal famous for their resilience. In examining the effects of radiation on organisms, an expert claimed that the amount of gamma radiation needed to sterilize a colony of tardigrades no longer has a mean of 900 Gy (grays). (For comparison, humans cannot withstand more than 10 Gy .) A study was conducted on a sample of 27 randomly selected tardigrade colonies, finding that the amount of gamma radiation needed to sterilize a colony had a sample mean of 907 Gy , with a sample standard deviation of 17 Gy . Assume that the population of amounts of gamma radiation needed to sterilize a colony of tardigrades is approximately normally distributed. Complete the parts below to perform a hypothesis test to see if there is enough evidence, at the 0.05 level of significance, to support the claim that μ , the mean amount of gamma radiation needed to sterilize a colony of tardigrades, is not equal to 900…arrow_forwardJ 2 RCT was conducted to evaluate efficacy and safety of drug simvastatin compared to placebo in reducing mortality and morbidity in patients with coronary heart disease. Subjects were followed up on average 5.4 years. Over the duration of the follow-up, 63 subjects died due to heart attack among 2,223 subjects in the placebo group compared to 30 deaths among 2,221 patients in the simvastatin drug group. 1. What is the Relative Risk or death from the heart attack in the simvastatin group?arrow_forward
- Tardigrades, or water bears, are a type of micro-animal famous for their resilience. In examining the effects of radiation on organisms, an expert claimed that the amount of gamma radiation needed to sterilize a colony of tardigrades no longer has a mean of 1350 Gy (grays). (For comparison, humans cannot withstand more than 10 Gy .) A study was conducted on a sample of 18 randomly selected tardigrade colonies, finding that the amount of gamma radiation needed to sterilize a colony had a sample mean of 1375 Gy , with a sample standard deviation of 75 Gy . Assume that the population of amounts of gamma radiation needed to sterilize a colony of tardigrades is approximately normally distributed. Complete the parts below to perform a hypothesis test to see if there is enough evidence, at the 0.05 level of significance, to support the claim that μ , the mean amount of gamma radiation needed to sterilize a colony of tardigrades, is not equal to 1350 Gy .arrow_forwardThe table below shows the numbers of bushels of barley cultivated per acre for 12 one-acre plots of land for two different strains of barley, PHT-34 and CBX-21. PHT-34 CBX-21 43 55 49 46 47 43 38 44 47 45 45 49 50 47 46 59 46 52 46 49 45 48 43 51 Determine the minimum data value, the quartiles, and the maximum data value for the PHT-34 and CBX-21 data sets. PHT-34 CBX-21 min Q1 Q2 Q3 maxarrow_forwardLow-Birth-Weight Hospital Stays. Data on low-birthweight babies were collected over a 2-year period by 14 participating centers of the National Institute of Child Health and Human Development Neonatal Research Network. Results were reported by J. Lemons et al. in the on-line paper “Very Low Birth Weight Outcomes of the National Institute of ChildHealth and Human Development Neonatal Research Network” (Pediatrics, Vol. 107, No. 1, p. e1). For the 1084 surviving babies whose birth weights were 751– 1000 grams, the average length of stay in the hospital was 86 days, although one center had an average of 66 days and another had an average of 108 days. a. Can the mean lengths of stay be considered population means? Explain your answer.b. Assuming that the population standard deviation is 12 days, determine the z-score for a baby’s length of stay of 86 days at the center where the mean was 66 days.c. Assuming that the population standard deviation is 12 days, determine the z-score for a…arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons Inc
Probability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage Learning
Statistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSON
The Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. Freeman
Introduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman
MATLAB: An Introduction with Applications
Statistics
ISBN:9781119256830
Author:Amos Gilat
Publisher:John Wiley & Sons Inc
Probability and Statistics for Engineering and th...
Statistics
ISBN:9781305251809
Author:Jay L. Devore
Publisher:Cengage Learning
Statistics for The Behavioral Sciences (MindTap C...
Statistics
ISBN:9781305504912
Author:Frederick J Gravetter, Larry B. Wallnau
Publisher:Cengage Learning
Elementary Statistics: Picturing the World (7th E...
Statistics
ISBN:9780134683416
Author:Ron Larson, Betsy Farber
Publisher:PEARSON
The Basic Practice of Statistics
Statistics
ISBN:9781319042578
Author:David S. Moore, William I. Notz, Michael A. Fligner
Publisher:W. H. Freeman
Introduction to the Practice of Statistics
Statistics
ISBN:9781319013387
Author:David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:W. H. Freeman
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