Probability and Statistics for Engineering and the Sciences
Probability and Statistics for Engineering and the Sciences
9th Edition
ISBN: 9781305251809
Author: Jay L. Devore
Publisher: Cengage Learning
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Textbook Question
Chapter 7.2, Problem 14E

The negative effects of ambient air pollution on children’s lung function has been well established, but less research is available about the impact of indoor air pollution. The authors of “Indoor Air Pollution and Lung Function Growth Among Children in Four Chinese Cities” (Indoor Air. 2012: 3–11) investigated the relationship between indoor air-pollution metrics and lung function growth among children ages 6–13 years living in four Chinese cities. For each subject in the study, the authors measured an important lung-capacity index known as FEV1 the forced volume (in ml) of air that is exhaled in 1 second. Higher FEV1 values are associated with greater lung capacity. Among the children in the study, 514 came from households that used coal for cooking or heating or both. Their FEV, mean was 1427 with a standard deviation of 325. (A complex statistical procedure was used to show that burning coal had a clear negative effect on mean FEV1 levels.)

  1. a. Calculate and interpret a 95% (two-sided) confidence interval for true average FEV1 level in the population of all children from which the sample was selected. Does it appear that the parameter of interest has been accurately estimated?
  2. b. Suppose the investigators had made a rough guess of 320 for the value of s before collecting data. What sample size would be necessary to obtain an interval width of 50 ml for a confidence level of 95%?
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Chapter 7 Solutions

Probability and Statistics for Engineering and the Sciences

Ch. 7.1 - Consider the next 1000 95% CIs for that a...Ch. 7.2 - The following observations are lifetimes (days)...Ch. 7.2 - The article Gas Cooking. Kitchen Ventilation, and...Ch. 7.2 - The negative effects of ambient air pollution on...Ch. 7.2 - Determine the confidence level for each of the...Ch. 7.2 - The alternating current (AC) breakdown voltage of...Ch. 7.2 - Exercise 1.13 gave a sample of ultimate tensile...Ch. 7.2 - The U.S. Army commissioned a study to assess how...Ch. 7.2 - The article Limited Yield Estimation for Visual...Ch. 7.2 - TV advertising agencies face increasing challenges...Ch. 7.2 - In a sample of 1000 randomly selected consumers...Ch. 7.2 - The technology underlying hip replacements has...Ch. 7.2 - The Pew Forum on Religion and Public Life reported...Ch. 7.2 - A sample of 56 research cotton samples resulted in...Ch. 7.2 - The Pew Forum on Religion and Public Life reported...Ch. 7.2 - The superintendent of a large school district,...Ch. 7.2 - Reconsider the CI (7.10) for p, and focus on a...Ch. 7.3 - Determine the values of the following quantities:...Ch. 7.3 - Determine the t critical value(s) that will...Ch. 7.3 - Determine the t critical value for a two-sided...Ch. 7.3 - Determine the t critical value for a lower or an...Ch. 7.3 - According to the article Fatigue Testing of...Ch. 7.3 - The article Measuring and Understanding the Aging...Ch. 7.3 - A sample of 14 joint specimens of a particular...Ch. 7.3 - Silicone implant augmentation rhinoplasty is used...Ch. 7.3 - A normal probability plot of the n = 26...Ch. 7.3 - A study of the ability of individuals to walk in a...Ch. 7.3 - Ultra high performance concrete (UHPC) is a...Ch. 7.3 - Exercise 72 of Chapter 1 gave the following...Ch. 7.3 - Prob. 40ECh. 7.3 - A more extensive tabulation of t critical values...Ch. 7.4 - Determine the values of the following quantities:...Ch. 7.4 - Determine the following: a. The 95th percentile of...Ch. 7.4 - The amount of lateral expansion (mils) was...Ch. 7.4 - Wire electrical-discharge machining (WEDM) is a...Ch. 7.4 - Wire electrical-discharge machining (WEDM) is a...Ch. 7 - Example 1.11 introduced the accompanying...Ch. 7 - The article Distributions of Compressive Strength...Ch. 7 - For those of you who dont already know, dragon...Ch. 7 - A journal article reports that a sample of size 5...Ch. 7 - Unexplained respiratory symptoms reported by...Ch. 7 - High concentration of the toxic element arsenic is...Ch. 7 - Aphid infestation of fruit trees can be controlled...Ch. 7 - It is important that face masks used by...Ch. 7 - A manufacturer of college textbooks is interested...Ch. 7 - The accompanying data on crack initiation depth...Ch. 7 - In Example 6.8, we introduced the concept of a...Ch. 7 - Prob. 58SECh. 7 - Prob. 59SECh. 7 - Prob. 60SECh. 7 - Prob. 61SECh. 7 - Prob. 62SE
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