Student Solutions Manual for Devore's Probability and Statistics for Engineering and the Sciences, 9th
9th Edition
ISBN: 9798214004020
Author: Jay L. Devore
Publisher: Cengage Learning US
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Textbook Question
Chapter 8, Problem 60SE
One method for straightening wire before coiling it to make a spring is called “roller straightening.” The article “The Effect of Roller and Spinner Wire Straightening on Coiling Performance and Wire Properties” (Springs, 1987: 27–28) reports on the tensile properties of wire. Suppose a sample of 16 wires is selected and each is tested to determine tensile strength (N/mm2). The resulting sample
- a. The mean tensile strength for springs made using spinner straightening is 2150 N/mm2. What hypotheses should be tested to determine whether the mean tensile strength for the roller method exceeds 2150?
- b. Assuming that the tensile strength distribution is approximately normal, what test statistic would you use to test the hypotheses in part (a)?
- c. What is the value of the test statistic for this data?
- d. What is the P-value for the value of the test statistic computed in part (c)?
- e. For a level .05 test, what conclusion would you reach?
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Chapter 8 Solutions
Student Solutions Manual for Devore's Probability and Statistics for Engineering and the Sciences, 9th
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...
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- A sociologist wants to know the proportion of adults with children under the age of 18 that eat dinner together 7 nights a week. A simple random sample of 1, 122 adults with children under the age of 18 was obtained, and 337 of those adults reported eating dinner together with their families 7 nights a week. a. Describe the parameter of interest. b. Describe the statistic of interest. What value of the statistic obtained?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 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_forward
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