Elementary Statistics: Picturing the World (6th Edition)
6th Edition
ISBN: 9780321911216
Author: Ron Larson, Betsy Farber
Publisher: PEARSON
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Textbook Question
Chapter 6, Problem 1RSRD
The Safe Drinking Water Act, which was passed in 1974, allows the Environmental Protection Agency (EPA) to regulate the levels of contaminants in drinking water. The EPA requires that water utilities give their customers water quality reports annually. These reports include the results of daily water quality monitoring, which is performed to determine whether drinking water is safe for consumption.
A water department tests for contaminants at water treatment plants and at customers laps. These contaminants include microorganisms, organic chemicals, and inorganic chemicals such as cyanide. Cyanide’s presence in drinking water is the result of discharges from Steel, plastics, and fertilizer factories. For drinking water, the maximum contaminant level of cyanide is 0.2 part per million.
As part of your job for your city’s water department, you are preparing a report that includes an analysis of the results shown in the figure at the right. The figure shows the point estimates for the population mean concentration and the 95% confidence intervals for μ for cyanide over a three-year period. The data are based on random water samples taken by the city’s three water treatment plants.
1. Interpreting the Results
Use the figure to determine whether there has been a change in the mean concentration level of cyanide for each time period. Explain your reasoning.
- (a) From Year 1 to Year 2
- (b) From Year 2 to Year 3
- (c) From Year 1 to Year 3
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Chapter 6 Solutions
Elementary Statistics: Picturing the World (6th Edition)
Ch. 6.1 - Prob. 1TYCh. 6.1 - Prob. 2TYCh. 6.1 - Prob. 3TYCh. 6.1 - Prob. 4TYCh. 6.1 - Prob. 5TYCh. 6.1 - Prob. 6TYCh. 6.1 - When estimating a population mean, are you more...Ch. 6.1 - Which statistic is the best unbiased estimator for...Ch. 6.1 - For the same sample statistics, which level of...Ch. 6.1 - You construct a 95% confidence interval for a...
Ch. 6.1 - In Exercises 58, find the critical value Zc...Ch. 6.1 - In Exercises 58, find the critical value Zc...Ch. 6.1 - In Exercises 58, find the critical value Zc...Ch. 6.1 - In Exercises 58, find the critical value Zc...Ch. 6.1 - Graphical Analysis In Exercises 912, use the...Ch. 6.1 - Graphical Analysis In Exercises 912, use the...Ch. 6.1 - Graphical Analysis In Exercises 912, use the...Ch. 6.1 - Graphical Analysis In Exercises 912, use the...Ch. 6.1 - In Exercises 1316, find the margin of error for...Ch. 6.1 - In Exercises 1316, find the margin of error for...Ch. 6.1 - In Exercises 1316, find the margin of error for...Ch. 6.1 - In Exercises 1316, find the margin of error for...Ch. 6.1 - Matching In Exercises 1720, match the level of...Ch. 6.1 - Matching In Exercises 1720, match the level of...Ch. 6.1 - Matching In Exercises 1720, match the level of...Ch. 6.1 - Matching In Exercises 1720, match the level of...Ch. 6.1 - In Exercises 2124, construct the indicated...Ch. 6.1 - In Exercises 2124, construct the indicated...Ch. 6.1 - In Exercises 2124, construct the indicated...Ch. 6.1 - In Exercises 2124, construct the indicated...Ch. 6.1 - In Exercises 2528, use the confidence interval to...Ch. 6.1 - In Exercises 2528, use the confidence interval to...Ch. 6.1 - In Exercises 2528, use the confidence interval to...Ch. 6.1 - In Exercises 2528, use the confidence interval to...Ch. 6.1 - In Exercises 2932, determine the minimum sample...Ch. 6.1 - In Exercises 2932, determine the minimum sample...Ch. 6.1 - In Exercises 2932, determine the minimum sample...Ch. 6.1 - In Exercises 2932, determine the minimum sample...Ch. 6.1 - Finding the Margin of Error In Exercises 33 and...Ch. 6.1 - Prob. 34ECh. 6.1 - Prob. 35ECh. 6.1 - Prob. 36ECh. 6.1 - Prob. 37ECh. 6.1 - Prob. 38ECh. 6.1 - Prob. 39ECh. 6.1 - Prob. 40ECh. 6.1 - Prob. 41ECh. 6.1 - Prob. 42ECh. 6.1 - When all other quantities remain the same, how...Ch. 6.1 - Prob. 44ECh. 6.1 - Prob. 45ECh. 6.1 - Prob. 46ECh. 6.1 - Determining a Minimum Sample Size Determine the...Ch. 6.1 - Determining a Minimum Sample Size Determine the...Ch. 6.1 - Prob. 49ECh. 6.1 - Prob. 50ECh. 6.1 - Prob. 51ECh. 6.1 - Prob. 52ECh. 6.1 - Prob. 53ECh. 6.1 - Prob. 54ECh. 6.1 - When all other quantities remain the same, how...Ch. 6.1 - When estimating the population mean, why not...Ch. 6.1 - Prob. 57ECh. 6.1 - Prob. 58ECh. 6.1 - Use the finite population correction factor to...Ch. 6.1 - Sample Size The equation for determining the...Ch. 6.2 - Prob. 1TYCh. 6.2 - Prob. 2TYCh. 6.2 - Prob. 3TYCh. 6.2 - Prob. 4TYCh. 6.2 - Finding Critical Values of t In Exercises 14, find...Ch. 6.2 - Finding Critical Values of t In Exercises 14, find...Ch. 6.2 - Finding Critical Values of t In Exercises 14, find...Ch. 6.2 - Finding Critical Values of t In Exercises 14, find...Ch. 6.2 - In Exercises 58, find the margin of error for the...Ch. 6.2 - In Exercises 58, find the margin of error for the...Ch. 6.2 - In Exercises 58, find the margin of error for the...Ch. 6.2 - In Exercises 58, find the margin of error for the...Ch. 6.2 - In Exercises 912, construct the indicated...Ch. 6.2 - In Exercises 912, construct the indicated...Ch. 6.2 - In Exercises 912, construct the indicated...Ch. 6.2 - In Exercises 912, construct the indicated...Ch. 6.2 - In Exercises 1316, use the confidence interval to...Ch. 6.2 - In Exercises 1316, use the confidence interval to...Ch. 6.2 - In Exercises 1316, use the confidence interval to...Ch. 6.2 - In Exercises 1316, use the confidence interval to...Ch. 6.2 - Constructing a Confidence Interval In Exercises...Ch. 6.2 - Constructing a Confidence Interval In Exercises...Ch. 6.2 - Prob. 19ECh. 6.2 - Prob. 20ECh. 6.2 - You research commute times to work and find that...Ch. 6.2 - You research driving distances to work and find...Ch. 6.2 - Prob. 23ECh. 6.2 - Prob. 24ECh. 6.2 - Prob. 25ECh. 6.2 - Prob. 26ECh. 6.2 - Constructing a Confidence Interval in Exercises...Ch. 6.2 - Constructing a Confidence Interval in Exercises...Ch. 6.2 - Prob. 29ECh. 6.2 - Prob. 30ECh. 6.2 - Choosing a Distribution In Exercises 3538, use the...Ch. 6.2 - Prob. 32ECh. 6.2 - Prob. 33ECh. 6.2 - Prob. 34ECh. 6.2 - Prob. 35ECh. 6.2 - Prob. 36ECh. 6.2 - Prob. 37ECh. 6.2 - Prob. 38ECh. 6.2 - Prob. 1ACh. 6.2 - In a random sample of 24 high school students, the...Ch. 6.2 - A marathon is a fool race with a distance of 26.22...Ch. 6.2 - A marathon is a fool race with a distance of 26.22...Ch. 6.2 - A marathon is a fool race with a distance of 26.22...Ch. 6.2 - A marathon is a fool race with a distance of 26.22...Ch. 6.2 - A marathon is a fool race with a distance of 26.22...Ch. 6.2 - A marathon is a fool race with a distance of 26.22...Ch. 6.3 - Prob. 1TYCh. 6.3 - Prob. 2TYCh. 6.3 - Prob. 3TYCh. 6.3 - Prob. 4TYCh. 6.3 - True or False? In Exercises 1 and 2, determine...Ch. 6.3 - True or False? In Exercises 1 and 2, determine...Ch. 6.3 - Prob. 3ECh. 6.3 - Prob. 4ECh. 6.3 - Prob. 5ECh. 6.3 - Prob. 6ECh. 6.3 - Prob. 7ECh. 6.3 - Prob. 8ECh. 6.3 - Prob. 9ECh. 6.3 - Prob. 10ECh. 6.3 - Prob. 11ECh. 6.3 - Prob. 12ECh. 6.3 - Prob. 13ECh. 6.3 - Prob. 14ECh. 6.3 - Prob. 15ECh. 6.3 - Prob. 16ECh. 6.3 - Prob. 17ECh. 6.3 - Prob. 18ECh. 6.3 - Prob. 19ECh. 6.3 - Prob. 20ECh. 6.3 - Prob. 21ECh. 6.3 - Prob. 22ECh. 6.3 - Prob. 23ECh. 6.3 - Prob. 24ECh. 6.3 - Prob. 25ECh. 6.3 - Prob. 26ECh. 6.3 - Prob. 27ECh. 6.3 - Prob. 28ECh. 6.3 - Prob. 29ECh. 6.3 - Prob. 30ECh. 6.3 - Prob. 31ECh. 6.3 - Prob. 1ACh. 6.3 - Prob. 2ACh. 6.4 - Prob. 1TYCh. 6.4 - Prob. 2TYCh. 6.4 - Does a population have to be normally distributed...Ch. 6.4 - What happens to the shape of the chi-square...Ch. 6.4 - Prob. 3ECh. 6.4 - Finding Critical Values for X2 In Exercises 38,...Ch. 6.4 - Prob. 5ECh. 6.4 - Finding Critical Values for X2 In Exercises 38,...Ch. 6.4 - Finding Critical Values for X2 In Exercises 38,...Ch. 6.4 - Prob. 8ECh. 6.4 - Prob. 9ECh. 6.4 - Prob. 10ECh. 6.4 - Prob. 11ECh. 6.4 - In Exercises 912, construct the indicated...Ch. 6.4 - Prob. 13ECh. 6.4 - Constructing Confidence Intervals In Exercises...Ch. 6.4 - Prob. 15ECh. 6.4 - Prob. 16ECh. 6.4 - Prob. 17ECh. 6.4 - Prob. 18ECh. 6.4 - Constructing Confidence Intervals In Exercises...Ch. 6.4 - Constructing Confidence Intervals In Exercises...Ch. 6.4 - Prob. 21ECh. 6.4 - Prob. 22ECh. 6.4 - Constructing Confidence Intervals In Exercises...Ch. 6.4 - Constructing Confidence Intervals In Exercises...Ch. 6.4 - Prob. 25ECh. 6.4 - Prob. 26ECh. 6.4 - Prob. 27ECh. 6 - The waking times (in minutes past 5:00 A.M.) of 40...Ch. 6 - The driving distances (in miles) to work of 30...Ch. 6 - Prob. 6.1.3RECh. 6 - Prob. 6.1.4RECh. 6 - In Exercises 5 and 6, use the confidence interval...Ch. 6 - Prob. 6.1.6RECh. 6 - Prob. 6.1.7RECh. 6 - Prob. 6.1.8RECh. 6 - In Exercises 912, find the critical value tc for...Ch. 6 - In Exercises 912, find the critical value tc for...Ch. 6 - In Exercises 912, find the critical value tc for...Ch. 6 - Prob. 6.2.12RECh. 6 - Prob. 6.2.13RECh. 6 - Prob. 6.2.14RECh. 6 - Prob. 6.2.15RECh. 6 - Prob. 6.2.16RECh. 6 - Prob. 6.2.17RECh. 6 - Prob. 6.2.18RECh. 6 - Prob. 6.2.19RECh. 6 - Prob. 6.2.20RECh. 6 - Prob. 6.2.21RECh. 6 - Prob. 6.2.22RECh. 6 - Prob. 6.3.23RECh. 6 - Prob. 6.3.24RECh. 6 - Prob. 6.3.25RECh. 6 - Prob. 6.3.26RECh. 6 - Prob. 6.3.27RECh. 6 - Prob. 6.3.28RECh. 6 - Prob. 6.3.29RECh. 6 - Prob. 6.3.30RECh. 6 - Prob. 6.3.31RECh. 6 - Prob. 6.3.32RECh. 6 - Prob. 6.4.33RECh. 6 - Prob. 6.4.34RECh. 6 - Prob. 6.4.35RECh. 6 - In Exercises 2730, find the critical values R2 and...Ch. 6 - Prob. 6.4.37RECh. 6 - Prob. 6.4.38RECh. 6 - Prob. 1CQCh. 6 - Prob. 2CQCh. 6 - The data set represents the amounts of time (in...Ch. 6 - Prob. 4CQCh. 6 - Prob. 5CQCh. 6 - Prob. 6CQCh. 6 - Prob. 1CTCh. 6 - Prob. 2CTCh. 6 - Prob. 3CTCh. 6 - Use the standard normal distribution or the...Ch. 6 - Prob. 5CTCh. 6 - The Safe Drinking Water Act, which was passed in...Ch. 6 - The Safe Drinking Water Act, which was passed in...Ch. 6 - The Safe Drinking Water Act, which was passed in...Ch. 6 - Prob. 4RSRDCh. 6 - Prob. 1TCh. 6 - Prob. 2TCh. 6 - Prob. 3TCh. 6 - Prob. 4TCh. 6 - Prob. 5T
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