Elementary Statistics: Picturing the World (7th Edition)

7th Edition

ISBN: 9780134683416

Author: Ron Larson, Betsy Farber

Publisher: PEARSON

See similar textbooks

Videos

Textbook Question

Chapter 6, Problem 3RSRD

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.

Chapter 6, Problem 3RSRD, The Safe Drinking Water Act, which was passed in 1974, allows the Environmental Protection Agency

3. What Do You Think?

The confidence interval for Year 2 is much larger than the other years. What do you think may have caused this larger confidence level?

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Chapter 6, Problem 2RSRD

Chapter 6, Problem 1T

Students have asked these similar questions

Periodically, the county Water Department tests the drinking water of homeowners for contaminants such as lead and copper. The lead and copper levels in water specimens collected in 1998 for a sample of 10 residents of a subdevelopement of the county are shown below. lead (μμg/L) copper (mg/L) 4.44.4 0.6430.643 2.42.4 0.570.57 1.51.5 0.460.46 2.62.6 0.8950.895 5.95.9 0.20.2 3.43.4 0.540.54 3.83.8 0.2450.245 1.61.6 0.5830.583 5.75.7 0.7690.769 1.71.7 0.2150.215 (a) Construct a 9999% confidence interval for the mean lead level in water specimans of the subdevelopment. ≤μ≤≤μ≤ (b) Construct a 9999% confidence interval for the mean copper level in water specimans of the subdevelopment. ≤μ≤≤μ≤

The National Hurricane Center provides data that list the number of large (category 3, 4, or 5) hurricanes that have struck the United States, by decade, from 1851-2020. Is there sufficient evidence that the number of large hurricanes have remained constant (per decade)? What are the degrees of freedom? Decade Count Decade Count 1851-1860 6 1941-1950 10 1861-1870 1 1951-1960 8 1871-1880 7 1961-1970 6 1881-1890 5 1971-1980 4 1891-1900 8 1981-1990 5 1901-1910 4 1991-2000 5 1911-1920 7 2001-2010 8 1921-1930 5 2011-2020 10 1931-1940 8 Chi-squared test for given probabilitiesdata: stormsX-squared = 13.589, df = 16, p-value = 0.6293 A. 107 B. 17 C. 13.589 D. 16

As part of a study designed to compare hybrid and similarly equipped conventional vehicles, a group tested a variety of classes of hybrid and all-gas model cars and sport utility vehicles (SUVs). Suppose the following data show the miles-per-gallon rating obtained for two hybrid small cars, two hybrid midsize cars, two hybrid small SUVs, and two hybrid midsize SUVs; also shown are the miles per gallon obtained for eight similarly equipped conventional models. Class Type MPG Small Car Hybrid 37 Small Car Conventional 28 Small Car Hybrid 44 Small Car Conventional 32 Midsize Car Hybrid 27 Midsize Car Conventional 23 Midsize Car Hybrid 32 Midsize Car Conventional 25 Small SUV Hybrid 27 Small SUV Conventional 21 Small SUV Hybrid 28 Small SUV Conventional 22 Midsize SUV Hybrid 23 Midsize SUV Conventional 19 Midsize SUV Hybrid 24 Midsize SUV Conventional 18 At the ? = 0.05 level of significance, test for significant effects due to class, type, and…

Chapter 6 Solutions

Elementary Statistics: Picturing the World (7th Edition)

Ch. 6.1 - In Example 1, the researcher selects a second...Ch. 6.1 - Use the data in Try It Yourself 1 and a 95%...Ch. 6.1 - Use the data in Try It Yourself 1 to construct a...Ch. 6.1 - Use the data in Example 1 and technology to...Ch. 6.1 - Construct a 90% confidence interval for the...Ch. 6.1 - In Example 6, how many student-athletes must the...Ch. 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...

Knowledge Booster

$Statistics$

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.

Solution Summary: The author explains why the confidence interval for Year 2 is larger than the other years because cyanide's presence in drinking water is the result of discharges from steel, plastics, and fertilizer factories.

Videos

Want to see the full answer?

Chapter 6 Solutions