Introduction to Statistical Quality Control
7th Edition
ISBN: 9781118146811
Author: Montgomery, Douglas C.
Publisher: John Wiley & Sons Inc
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Textbook Question
Chapter 4, Problem 38E
Compare the mean compressive strength at each rodding level from Exercise 4.37 with a scaled t distribution. What conclusions would you draw from this plot?
4.37. An article in the ACI Materials Journal (Vol. 84, 1987, pp. 213–216) describes several experiments investigating the rodding of concrete to remove entrapped air. A 3-in.-diameter cylinder was used, and the number of times this rod was used is the design variable. The resulting compressive strength of the concrete specimen is the response. The data are shown in Table 4E.5.
TABLE 4E.5
Compressive Strength Data for Exercise 4.37
- (a) Is there any difference in compressive strength due to the rodding level? Answer this question by using the analysis of variance with α = 0.05.
- (b) Construct box plots of compressive strength by rodding level. Provide a practical interpretation of these plots.
- (c) Construct a normal probability plot of the residuals from this experiment. Does the assumption of a
normal distribution for compressive strength seem reasonable?
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Chapter 4 Solutions
Introduction to Statistical Quality Control
Ch. 4 - Suppose that you are testing the following...Ch. 4 - Suppose that you are testing the following...Ch. 4 - Suppose that you are testing the following...Ch. 4 - Suppose that you are testing the following...Ch. 4 - Suppose that you are testing the following...Ch. 4 - Suppose that you are testing the following...Ch. 4 - The inside diameters of bearings used in an...Ch. 4 - The tensile strength of a fiber used in...Ch. 4 - The service life of a battery used in a cardiac...Ch. 4 - Using the data from Exercise 4.7, construct a 95%...
Ch. 4 - A new process has been developed for applying...Ch. 4 - A machine is used to fill containers with a liquid...Ch. 4 - Ferric chloride is used as a flux in some types of...Ch. 4 - The diameters of aluminum alloy rods produced on...Ch. 4 - The output voltage of a power supply is assumed to...Ch. 4 - Two machines are used for filling glass bottles...Ch. 4 - Two quality control technicians measured the...Ch. 4 - Suppose that x1N(,12) and x2N(2,22), and that x1...Ch. 4 - Two different hardening processes(1) saltwater...Ch. 4 - A random sample of 200 printed circuit boards...Ch. 4 - A random sample of 500 connecting rod pins...Ch. 4 - Two processes are used to produce forgings used in...Ch. 4 - A new purification unit is installed in a chemical...Ch. 4 - Two different types of glass bottles are suitable...Ch. 4 - The diameter of a metal rod is measured by 12...Ch. 4 - The cooling system in a nuclear submarine consists...Ch. 4 - An experiment was conducted to investigate the...Ch. 4 - Suppose we wish to test the hypotheses H0:=15H1:15...Ch. 4 - Consider the hypotheses H0:=0H1:0 where 2 is...Ch. 4 - Sample size allocation. Suppose we are testing the...Ch. 4 - Develop a test for the hypotheses H0: 1 = 2 H1: 1 ...Ch. 4 - Nonconformities occur in glass bottles according...Ch. 4 - An inspector counts the surface-finish defects in...Ch. 4 - An in-line tester is used to evaluate the...Ch. 4 - An article in Solid State Technology (May 1987)...Ch. 4 - Compare the mean etch uniformity values at each of...Ch. 4 - An article in the ACI Materials Journal (Vol. 84,...Ch. 4 - Compare the mean compressive strength at each...Ch. 4 - An aluminum producer manufactures carbon anodes...Ch. 4 - Plot the residuals from Exercise 4.36 against the...Ch. 4 - An article in Environmental International (Vol....Ch. 4 - An article in the Journal of the Electrochemical...Ch. 4 - The tensile strength of a paper product is related...Ch. 4 - A plant distills liquid air to produce oxygen,...Ch. 4 - Plot the residuals from Exercise 4.43 and comment...Ch. 4 - Plot the residuals from Exercise 4.44 and comment...Ch. 4 - The brake horsepower developed by an automobile...Ch. 4 - Analyze the residuals from the regression model in...Ch. 4 - Table 4E.11 contains the data from a patient...Ch. 4 - Analyze the residuals from the regression model on...Ch. 4 - Reconsider the patient satisfaction data in Table...Ch. 4 - Analyze the residuals from the multiple regression...Ch. 4 - Consider the Minitab output below. (a) Fill in the...Ch. 4 - Suppose that you are testing H0: 1 = 2 versus H1: ...Ch. 4 - Suppose that you are testing H0: = 2 versus H1: ...Ch. 4 - Consider the Minitab output below. (a) Fill in the...Ch. 4 - Consider the Minitab output shown below. (a) Is...Ch. 4 - Consider the Minitab output shown below. (a) Fill...Ch. 4 - Consider the Minitab output below. (a) Fill in the...Ch. 4 - Consider a one-way or single-factor ANOVA with...Ch. 4 - Consider the Minitab ANOVA output below. Fill in...
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