Statistics for Engineers and Scientists
4th Edition
ISBN: 9780073401331
Author: William Navidi Prof.
Publisher: McGraw-Hill Education
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Chapter 5.4, Problem 14E
The article “Occurrence and Distribution of Ammonium in Iowa Groundwater” (K. Schilling, Water Environment Research, 2002:177–186) describes measurements of ammonium concentrations (in mg/L) at a large number of wells in the state of Iowa. These included 349 alluvial wells and 143 quaternary wells. The concentrations at the alluvial wells averaged 0.27 with a standard deviation of 0.40, and those at the quaternary wells averaged 1.62 with a standard deviation of 1.70. Find a 95% confidence interval for the difference in mean concentrations between alluvial and quaternary wells.
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In the article “Occurrence and Distribution of Ammonium in Iowa Groundwater” (K.Schilling, Water Environment Research, 2002:177–186), ammonium concentrations (inmg/L) were measured at a total of 349 alluvial wells in the state of Iowa. The mean concentration was 0.27, the median was 0.10, and the standard deviation was 0.40. If a histogram of these 349 measurements were drawn,a) it would be most likely skewed to the right.b) it would be most likely skewed to the left.c) it would be approximately symmetric.d) its shape could not be determined without knowing the relative frequencies.
The annual rainfall in a certain region is modeled using the normal distribution shown below.
The mean of the distribution is 36.5 cm and the standard deviation is 5.2 cm.
In the figure, V is a number along the axis and is under the highest part of the curve.
And, U and W are numbers along the axis that are each the same distance away from V.
Use the empirical rule to choose the best value for the percentage of the area under the curve that is shaded, and find the values of U, V, and W.
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The annual rainfall in a certain region is modeled using the normal distribution shown below.
The mean of the distribution is 36.9 cm and the standard deviation is 4.8 cm.
In the figure, V is a number along the axis and is under the highest part of the curve.
And, U and W are numbers along the axis that are each the same distance away from V.
Use the empirical rule to choose the best value for the percentage of the area under the curve that is shaded, and find the values of U, V, and W.
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Chapter 5 Solutions
Statistics for Engineers and Scientists
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
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