Statistics for Engineers and Scientists - With Access
4th Edition
ISBN: 9781259275975
Author: Navidi
Publisher: MCG
expand_more
expand_more
format_list_bulleted
Textbook Question
Chapter 5.1, Problem 4E
The article “Modeling Arterial Signal Optimization with Enhanced Cell Transmission Formulations” (Z. Li, Journal of Transportation Engineering 2011:445–454) presents a new method for timing traffic signals in heavily traveled intersections. The effectiveness of the new method was evaluated in a simulation study. In 50 simulations, the mean improvement in traffic flow in a particular intersection was 654.1 vehicles per hour, with a standard deviation of 311.7 vehicles per hour.
- a. Find a 95% confidence interval for the improvement in traffic flow due to the new system.
- b. Find a 98% confidence interval for the improvement in traffic flow due to the new system.
- c. A traffic engineer states that the mean improvement is between 581.6 and 726.6 vehicles per hour. With what level of confidence can this statement be made?
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
The article “Wind-Uplift Capacity of Residential Wood Roof-Sheathing Panels Retrofitted with Insulating Foam Adhesive” (P. Datin, D. Prevatt, and W. Pang, Journal of Architectural Engineering, 2011:144–154) presents a study of the failure pressures of roof panels. Following are the failure pressures, in kPa, for five panels constructed with 6d smooth shank nails. These data are consistent with means and standard deviations presented in the article. 3.32 2.53 3.45 2.38 3.01 Find a 95% confidence interval for the mean failure pressure for this type of roof panel.
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
.
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…
Chapter 5 Solutions
Statistics for Engineers and Scientists - With Access
Ch. 5.1 - Find the value of Z/2 to use in expression (5.1)...Ch. 5.1 - Find the levels of the confidence intervals that...Ch. 5.1 - As the confidence level goes up, the reliability...Ch. 5.1 - The article Modeling Arterial Signal Optimization...Ch. 5.1 - In a sample of 100 steel wires the average...Ch. 5.1 - The article Application of Surgical Navigation to...Ch. 5.1 - The capacities (in ampere-hours) were measured for...Ch. 5.1 - Oven thermostats were tested by setting them to...Ch. 5.1 - In a sample of 80 ten-penny nails, the average...Ch. 5.1 - In a sample of 60 electric motors, the average...
Ch. 5.1 - The sugar content in a one-cup serving of a...Ch. 5.1 - Refer to Exercise 5. a. Find a 95% lower...Ch. 5.1 - Prob. 13ECh. 5.1 - Prob. 14ECh. 5.1 - Prob. 15ECh. 5.1 - Refer to Exercise 9. a. Find a 90% upper...Ch. 5.1 - Refer to Exercise 10. a. Find a 98% lower...Ch. 5.1 - Refer to Exercise 11. a. Find a 95% upper...Ch. 5.1 - Prob. 19ECh. 5.1 - A 95% confidence interval for a population mean is...Ch. 5.1 - Based on a large sample of capacitors of a certain...Ch. 5.1 - Sixty-four independent measurements were made of...Ch. 5.1 - A large box contains 10,000 ball bearings. A...Ch. 5.1 - Prob. 24ECh. 5.1 - Prob. 25ECh. 5.1 - Prob. 26ECh. 5.2 - In a simple random sample of 70 automobiles...Ch. 5.2 - During a recent drought, a water utility in a...Ch. 5.2 - A soft-drink manufacturer purchases aluminum cans...Ch. 5.2 - The article HIV-positive Smokers Considering...Ch. 5.2 - The article The Functional Outcomes of Total Knee...Ch. 5.2 - Refer to Exercise 1. Find a 95% lower confidence...Ch. 5.2 - Refer to Exercise 2. Find a 98% upper confidence...Ch. 5.2 - Refer to Exercise 4. Find a 99% lower confidence...Ch. 5.2 - A random sample of 400 electronic components...Ch. 5.2 - Refer to Exercise 9. A device will be manufactured...Ch. 5.2 - When the light turns yellow, should you stop or go...Ch. 5.2 - In a random sample of 150 customers of a...Ch. 5.2 - A sociologist is interested in surveying workers...Ch. 5.2 - Stainless steels can be susceptible to stress...Ch. 5.2 - The article A Music Key Detection Method Based on...Ch. 5.2 - A stock market analyst notices that in a certain...Ch. 5.3 - Find the value of tn1,/2 needed to construct a...Ch. 5.3 - Find the value of tn1, needed to construct an...Ch. 5.3 - Find the level of a two-sided confidence interval...Ch. 5.3 - True or false: The Students t distribution may be...Ch. 5.3 - The article Wind-Uplift Capacity of Residential...Ch. 5.3 - Prob. 6ECh. 5.3 - The article An Automatic Visual System for Marble...Ch. 5.3 - A chemist made eight independent measurements of...Ch. 5.3 - Six measurements are taken of the thickness of a...Ch. 5.3 - Fission tracks are trails found in uranium-bearing...Ch. 5.3 - The article Effect of Granular Subbase Thickness...Ch. 5.3 - The article Influence of Penetration Rate on...Ch. 5.3 - Prob. 13ECh. 5.3 - Prob. 14ECh. 5.3 - Prob. 15ECh. 5.3 - The concentration of carbon monoxide (CO) in a gas...Ch. 5.3 - The article Filtration Rates of the Zebra Mussel...Ch. 5.4 - To study the effect of curing temperature on shear...Ch. 5.4 - The article Some Parameters of the Population...Ch. 5.4 - The article Inconsistent Health Perceptions for US...Ch. 5.4 - The article Hatching Distribution of Eggs Varying...Ch. 5.4 - The article Automatic Filtering of Outliers in RR...Ch. 5.4 - A group of 78 people enrolled in a weight-loss...Ch. 5.4 - In experiments to determine the effectiveness of...Ch. 5.4 - A stress analysis was conducted on random samples...Ch. 5.4 - In a study to compare two different corrosion...Ch. 5.4 - An electrical engineer wishes to compare the mean...Ch. 5.4 - In a study of the effect of cooling rate on the...Ch. 5.4 - Refer to Exercise 11. Ten more welds will be made...Ch. 5.4 - The article The Prevalence of Daytime Napping and...Ch. 5.4 - The article Occurrence and Distribution of...Ch. 5.5 - In a test of the effect of dampness on electric...Ch. 5.5 - The specification for the pull strength of a wire...Ch. 5.5 - Angioplasty is a medical procedure in which an...Ch. 5.5 - Prob. 4ECh. 5.5 - Prob. 5ECh. 5.5 - Prob. 6ECh. 5.5 - In a study of contamination at landfills...Ch. 5.5 - Prob. 8ECh. 5.5 - A mobile computer network consists of a number of...Ch. 5.5 - The article Evaluation of Criteria for Setting...Ch. 5.5 - In a certain year, there were 80 days with...Ch. 5.6 - In a study comparing various methods of gold...Ch. 5.6 - Prob. 2ECh. 5.6 - In an experiment involving the breaking strength...Ch. 5.6 - A new post-surgical treatment is being compared...Ch. 5.6 - The article Differences in Susceptibilities of...Ch. 5.6 - The article Tibiofemoral Cartilage Thickness...Ch. 5.6 - During the spring of 1999, many fuel storage...Ch. 5.6 - Prob. 8ECh. 5.6 - The article Toward a Lifespan Metric of Reading...Ch. 5.6 - Prob. 10ECh. 5.6 - Measurements of the sodium content in samples of...Ch. 5.6 - Prob. 12ECh. 5.6 - Prob. 13ECh. 5.6 - In the article Bactericidal Properties of Flat...Ch. 5.6 - Prob. 15ECh. 5.7 - The article Simulation of the Hot Carbonate...Ch. 5.7 - The article Effect of Refrigeration on the...Ch. 5.7 - Transepidermal water loss (TEWL) is a measure of...Ch. 5.7 - Breathing rates, in breaths per minute, were...Ch. 5.7 - A group of five individuals with high blood...Ch. 5.7 - A sample of 10 diesel trucks were run both hot and...Ch. 5.7 - For a sample of nine automobiles, the mileage (in...Ch. 5.7 - Prob. 8ECh. 5.7 - Prob. 9ECh. 5.7 - Prob. 10ECh. 5.8 - Find the following values. a. 12,.0252 b. 12,.9752...Ch. 5.8 - Prob. 2ECh. 5.8 - Construct a 99% confidence interval for the...Ch. 5.8 - Prob. 4ECh. 5.8 - Scores on an IQ test are normally distributed. A...Ch. 5.8 - Prob. 6ECh. 5.8 - Boxes of cereal are labeled as containing 14...Ch. 5.8 - Prob. 8ECh. 5.8 - Following are interest rates (annual percentage...Ch. 5.8 - Prob. 10ECh. 5.8 - Prob. 11ECh. 5.8 - Prob. 12ECh. 5.9 - A sample of 25 resistors, each labeled 100, had an...Ch. 5.9 - Prob. 2ECh. 5.9 - The article Ozone for Removal of Acute Toxicity...Ch. 5.9 - Six measurements were made of the concentration...Ch. 5.9 - Five measurements are taken of the octane rating...Ch. 5 - A molecular biologist is studying the...Ch. 5 - Prob. 2SECh. 5 - The article Genetically Based Tolerance to...Ch. 5 - A sample of 87 glass sheets has a mean thickness...Ch. 5 - Prob. 5SECh. 5 - Prob. 6SECh. 5 - Leakage from underground fuel tanks has been a...Ch. 5 - Prob. 8SECh. 5 - Prob. 9SECh. 5 - Prob. 10SECh. 5 - In the article Groundwater Electromagnetic Imaging...Ch. 5 - Prob. 12SECh. 5 - Prob. 13SECh. 5 - Prob. 14SECh. 5 - A metallurgist makes several measurements of the...Ch. 5 - In a study of the lifetimes of electronic...Ch. 5 - The temperature of a certain solution is estimated...Ch. 5 - Prob. 18SECh. 5 - Prob. 19SECh. 5 - The answer to Exercise 19 part (d) is needed for...Ch. 5 - The carbon content (in ppm) was measured for each...Ch. 5 - Diameters, in mm, were measured for eight...Ch. 5 - A sample of eight repair records for a certain...Ch. 5 - Prob. 25SE
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
- 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_forwardNutritionResearchers compared protein intake among threegroups of postmenopausal women: (1) women eating astandard American diet (STD), (2) women eating a lactoovo-vegetarian diet (LAC), and (3) women eating a strictvegetarian diet (VEG). The mean ± 1 sd for protein intake(mg) is presented in Table 12.29. 12.5 Using the data in Table 12.29, perform a multiplecomparisons procedure to identify which specific underlyingmeans are different.arrow_forwardThe article “Wind-Uplift Capacity of Residential Wood Roof-Sheathing Panels Retrofitted with Insulating Foam Adhesive” (P. Datin, D. Prevatt, and W. Pang, Journal of Architectural Engineering, 2011:144–154) presents a study of the failure pressures of roof panels. A sample of 15 panels constructed with 8-inch nail spacing on the intermediate framing members had a mean failure pressure of 8.38 kPa with a standard deviation of 0.96 kPa. A sample of 15 panels constructed with 6-inch nail spacing on the intermediate framing members had a mean failure pressure of 9.83 kPa with a standard deviation of 1.02 kPa. Can you conclude that 6-inch spacing provides a higher mean failure pressure?arrow_forward
- 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.arrow_forwardNutritionResearchers compared protein intake among threegroups of postmenopausal women: (1) women eating astandard American diet (STD), (2) women eating a lactoovo-vegetarian diet (LAC), and (3) women eating a strictvegetarian diet (VEG). The mean ± 1 sd for protein intake(mg) is presented in Table 12.29.*12.1 Perform a statistical procedure to comparethe means of the three groups using the critical-valuemethod.arrow_forwardA study on the oxygen consumption rate (OCR) of sea cucumbers involved a random sample of size 12 at 15oC and a second random sample of size 5 kept at 18oC. To test the hypothesis that this range of temperature had no effect on the OCR, what is the degrees of freedom for a two-sample t-test?arrow_forward
- In building an arena , steel bars with a mean ultimate tensile strength of 400 Megapascal (MPa ) with a variance of 81 MPa were delivered by the manufacturer . The project engineer tested 50 steel bars and found out that the mean ultimate tensile strength is 390 MPa The decision for the extension of the contract with the manufacture depends on the engineer . Test the hypothesis whether or not there is no significant difference between the two means using a two-tailed test with a = 0.01 1. What are the appropriate hypotheses for the two tailed test ? 2. What is the test statistic to be used and the reasons for its selection ? 3. What is the critical value c? 4. What is the value of the test statistic or the computed value? 5. Formulate a conclusion about the given situationarrow_forwardThe article “Predicting Depressed Patients with Suicidal Ideation from ECG Recordings” (A. Khandoker, V. Luthra, et al., Med Biol Eng Comput, 2017:793–805) reports a study in which systolic blood pressure (in mmHg) was measured for 16 patients suffering from depression and for 29 controls. Those with depression averaged 112.50 with a standard deviation of 13.90, and the controls averaged 110.34 with a standard deviation of 8.65. Can you conclude that the mean systolic blood pressure is higher in those suffering from depression?arrow_forwardSince its removal from the banned substances list in 2004 by the World Anti-Doping Agency,caffeine has been used by athletes with the expectancy that it enhances their workout andperformance. However, few studies look at the role caffeine plays in sedentary females.Researchers at the University of Western Australia conducted a test in which they determined therate of energy expenditure (kilojoules) on 10 healthy, sedentary females who were nonregularcaffeine users. Each female was randomly assigned either a placebo or caffeine pill (6mg/kg) 60minutes prior to exercise. The subject rode an exercise bike for 15 minutes at 65% of theirmaximum heart rate, and the energy expenditure was measured. The process was repeated on aseparate day for the remaining treatment. The mean difference in energy expenditure (caffeine –placebo) was 18kJ with a standard deviation of 19kJ. If we assume that the differences follow anormal distribution can it be concluded that that caffeine appears to increase…arrow_forward
- A quality analyst conducts a small-scale study to compare the average capacity of two brands of AA batteries (A and B). A random sample of 10 batteries of Brand A has an average capacity of 1065 mAh (milliampere-hours), and an independent random sample of 10 batteries of Brand B has an average capacity of 994 mAh. The sample standard deviations are 23.6 mAh and 38.0 mAh, respectively. It is assumed that battery capacity is normally distributed for both brands and the two distributions have the same variance. Find the upper limit of a 95% confidence interval for the difference between the population means. Form the confidence interval around a positive point estimate for the difference between the means. In order to obtain a positive point estimate, make sure you subtract the lower value from the higher value when calculating the difference between the sample means. (Provide your answer as a number rounded to the nearest integer.)arrow_forwardThis chart shows the results of two random samples that measured the average number of minutes per charge for AA Lithium-ion (Li-ion) rechargeable batteries versus Nickel-Metal Hydride (NiMH) rechargeable batteries. Down below shows the hypothesis test using significance level (α) = 0.05 to determine if the true average number of minutes per charge for NiMH batteries is smaller than that for Li-ion batteries. 1. From the data given from the first graph below, what would be the correct p value? (the one tail or the two tail?) t-Test: Two-Sample Assuming Unequal Variances NiMH Li-ion Mean 89.35714 95 Variance 3.93956 59.75 Observations 14 17 Hypothesized Mean Difference 0 df 19 t Stat -2.89621 P(T<=t) one-tail 0.004628 t Critical one-tail 1.729133 P(T<=t) two-tail 0.009255 t Critical two-tail 2.093024 For the bottom graph: 1.. Find the point estimate (you can do this by subtracting Group 2…arrow_forwardA physician compared the cholesterol levels of a representative sample of Americans who ate an American diet versus a representative sample of those who followed a Mediterranean diet. Below are the means, standard deviations, and sample sizes for both samples. Though in some studies a Mediterranean diet has been shown to be beneficial, this was one of the first studies on an American population and the physician had made no advance predictions about the outcome. American diet (control): M = 230, s = 24, n = 36. Mediterranean (experimental): M = 190, s = 26, n = 36. Use α = .05. 6. Calculate the test statistic 7. Estimate the magnitude of the effect size (Cohen’s d). 8. Calculate the 95% confidence interval for the differences between population means.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 IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics 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:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction 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
Hypothesis Testing using Confidence Interval Approach; Author: BUM2413 Applied Statistics UMP;https://www.youtube.com/watch?v=Hq1l3e9pLyY;License: Standard YouTube License, CC-BY
Hypothesis Testing - Difference of Two Means - Student's -Distribution & Normal Distribution; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=UcZwyzwWU7o;License: Standard Youtube License