Elementary Statistics, Books A La Carte Edition (13th Edition)
13th Edition
ISBN: 9780134463063
Author: Mario F. Triola
Publisher: PEARSON
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Textbook Question
Chapter 3.2, Problem 45BB
Why Divide by n − 1? Let a population consist of the values 9 cigarettes, 10 cigarettes, and 20 cigarettes smoked in a day (based on data from the California Health Interview Survey). Assume that samples of two values are randomly selected with replacement from this population. (That is, a selected value is replaced before the second selection is made.)
a. Find the variance σ2 of the population {9 cigarettes, 10 cigarettes, 20 cigarettes}.
b. After listing the nine different possible samples of two values selected with replacement, find the sample variance s2 (which includes division by n − 1) for each of them; then find then
c. For each of the nine different possible samples of two values selected with replacement, find the variance by treating each sample as if it is a population (using the formula for population variance, which includes division by n); then find the mean of those nine population variances.
d. Which approach results in values that are better estimates of σ2: part (b) or part (c)? Why? When computing variances of samples, should you use division by n or n − 1?
e. The preceding parts show that s2 is an unbiased estimator of σ2. Is s an unbiased estimator of σ? Explain.
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Chapter 3 Solutions
Elementary Statistics, Books A La Carte Edition (13th Edition)
Ch. 3.1 - Average The defunct website IncomeTaxList.com...Ch. 3.1 - Whats Wrong? USA Today published a list consisting...Ch. 3.1 - Measures of Center In what sense are the mean,...Ch. 3.1 - Resistant Measures Here are four of the Verizon...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...
Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - Critical Thinking. For Exercises 5-20, watch out...Ch. 3.1 - In Exercises 21-24, find the mean and median for...Ch. 3.1 - In Exercises 21-24, find the mean and median for...Ch. 3.1 - In Exercises 21-24, find the mean and median for...Ch. 3.1 - In Exercises 21-24, find the mean and median for...Ch. 3.1 - Large Data Sets from Appendix B. In Exercises...Ch. 3.1 - Large Data Sets from Appendix B. In Exercises...Ch. 3.1 - Large Data Sets from Appendix B. In Exercises...Ch. 3.1 - Large Data Sets from Appendix B. In Exercises...Ch. 3.1 - In Exercises 29-32, find the mean of the data...Ch. 3.1 - In Exercises 29-32, find the mean of the data...Ch. 3.1 - In Exercises 29-32, find the mean of the data...Ch. 3.1 - In Exercises 29-32, find the mean of the data...Ch. 3.1 - Weighted Mean A student of the author earned...Ch. 3.1 - Weighted Mean A student of the author earned...Ch. 3.1 - Degrees of Freedom Five pulse rates randomly...Ch. 3.1 - Censored Data Data Set 15 Presidents in Appendix B...Ch. 3.1 - Trimmed Mean Because the mean is very sensitive to...Ch. 3.1 - Harmonic Mean The harmonic mean is often used as a...Ch. 3.1 - Geometric Mean The geometric mean is often used in...Ch. 3.1 - Quadratic Mean The quadratic mean (or root mean...Ch. 3.1 - Median When data are summarized in a frequency...Ch. 3.2 - Range Rule of Thumb for Estimating s The 20 brain...Ch. 3.2 - Range Rule of Thumb for Interpreting s The 20...Ch. 3.2 - Variance The 20 subjects used in Data Set 8 IQ and...Ch. 3.2 - Symbols Identify the symbols used for each of the...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 5-20, find the range, variance, and...Ch. 3.2 - In Exercises 21-24, find the coefficient of...Ch. 3.2 - In Exercises 21-24, find the coefficient of...Ch. 3.2 - In Exercises 21-24, find the coefficient of...Ch. 3.2 - In Exercises 21-24, find the coefficient of...Ch. 3.2 - Large Data Sets from Appendix B. In Exercises...Ch. 3.2 - Prob. 26BSCCh. 3.2 - Large Data Sets from Appendix B. In Exercises...Ch. 3.2 - Large Data Sets from Appendix B. In Exercises...Ch. 3.2 - Estimating Standard Deviation with the Range Rule...Ch. 3.2 - Prob. 30BSCCh. 3.2 - Estimating Standard Deviation with the Range Rule...Ch. 3.2 - Estimating Standard Deviation with the Range Rule...Ch. 3.2 - Identifying Significant Values with the Range Rule...Ch. 3.2 - Prob. 34BSCCh. 3.2 - Foot Lengths Based on Data Set 2 Foot and Height...Ch. 3.2 - Identifying Significant Values with the Range Rule...Ch. 3.2 - Finding Standard Deviation from a Frequency...Ch. 3.2 - Finding Standard Deviation from a Frequency...Ch. 3.2 - Finding Standard Deviation from a Frequency...Ch. 3.2 - Finding Standard Deviation from a Frequency...Ch. 3.2 - The Empirical Rule Based on Data Set 1 Body Data...Ch. 3.2 - The Empirical Rule Based on Data Set 3 Body...Ch. 3.2 - Chebyshevs Theorem Based on Data Set 1 Body Data...Ch. 3.2 - Chebyshevs Theorem Based on Data Set 3 Body...Ch. 3.2 - Why Divide by n 1? Let a population consist of...Ch. 3.2 - Mean Absolute Deviation Use the same population of...Ch. 3.3 - z Scores LeBron James, one of the most successful...Ch. 3.3 - Heights The boxplot shown below results from the...Ch. 3.3 - Boxplot Comparison Refer to the boxplots shown...Ch. 3.3 - z Scores If your score on your next statistics...Ch. 3.3 - z Scores. In Exercises 5-8, express all z scores...Ch. 3.3 - z Scores. In Exercises 5-8, express all z scores...Ch. 3.3 - z Scores. In Exercises 5-8, express all z scores...Ch. 3.3 - z Scores. In Exercises 5-8, express all z scores...Ch. 3.3 - Significant Values. In Exercises 9-12, consider a...Ch. 3.3 - Significant Values. In Exercises 9-12, consider a...Ch. 3.3 - Significant Values. In Exercises 9-12, consider a...Ch. 3.3 - Significant Values. In Exercises 9-12, consider a...Ch. 3.3 - Comparing Values. In Exercises 13-16, use z scores...Ch. 3.3 - Comparing Values. In Exercises 13-16, use z scores...Ch. 3.3 - Comparing Values. In Exercises 13-16, use z scores...Ch. 3.3 - Comparing Values. In Exercises 13-16, use z scores...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Percentiles. In Exercises 17-20, use the following...Ch. 3.3 - Boxplots. In Exercises 29-32, use the given data...Ch. 3.3 - Boxplots. In Exercises 29-32, use the given data...Ch. 3.3 - Boxplots. In Exercises 29-32, use the given data...Ch. 3.3 - Boxplots. In Exercises 29-32, use the given data...Ch. 3.3 - Boxplots from Large Data Sets in Appendix B. In...Ch. 3.3 - Boxplots from Large Data Sets in Appendix B. In...Ch. 3.3 - Prob. 35BSCCh. 3.3 - Boxplots from Large Data Sets in Appendix B. In...Ch. 3.3 - Outliers and Modified Boxplots Repeat Exercise 33...Ch. 3 - Sleep Mean As part of the National Health and...Ch. 3 - Sleep Median What is the median of the sample...Ch. 3 - Sleep Mode What is the mode of the sample values...Ch. 3 - Sleep Variance The standard deviation of the...Ch. 3 - Prob. 5CQQCh. 3 - Sleep z Score A larger sample of 50 sleep times...Ch. 3 - Sleep Q3 For a sample of 80 sleep times,...Ch. 3 - Sleep 5-Number Summary For a sample of 100 sleep...Ch. 3 - Estimating s A large sample of sleep times...Ch. 3 - Sleep Notation Consider a sample of sleep times...Ch. 3 - Old Faithful Geyser Listed below are prediction...Ch. 3 - z Score Using the sample data from Exercise 1,...Ch. 3 - Boxplot Using the same prediction errors listed in...Ch. 3 - ER Codes In an analysis of activities that...Ch. 3 - Comparing Birth Weights The birth weights of a...Ch. 3 - Effects of an Outlier Listed below are platelet...Ch. 3 - Interpreting a Boxplot Shown below is a boxplot of...Ch. 3 - Estimating Standard Deviation Listed below is a...Ch. 3 - Prob. 1CRECh. 3 - Prob. 2CRECh. 3 - Stemplot Use the amounts of arsenic from Exercise...Ch. 3 - Prob. 4CRECh. 3 - Histogram The accompanying histogram depicts...Ch. 3 - Normal Distribution Examine the distribution shown...Ch. 3 - Words Spoken by Men and Women Refer to Data Set 24...Ch. 3 - Second-Hand Smoke Data Set 12 Passive and Active...
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