ELEMENTARY STATISTICS PKG. F13
13th Edition
ISBN: 9781269373333
Author: Triola
Publisher: PEARSON C
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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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The table below shows the prices (R) and quantities (kg) of rice, meat and potatoes items bought during 2013 and 2014:
2013
2014
P1Qo
PoQo
Q1Po P1Q1
Price
Ро
Quantity
Qo
Price
P1
Quantity
Q1
Rice
7
80
6
70
480
560
490
420
Meat
30
50
35
60
1 750
1 500
1 800
2 100
Potatoes
3
100
3
100
300
300
300
300
TOTAL
40
230
44
230
2 530
2 360
2 590
2 820
Instructions:
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ENG US
口X
2025/05
The table below indicates the number of years of experience of a sample of employees who work on a particular production line and the corresponding number of units of a good that each employee produced last month.
Years of Experience (x)
Number of Goods (y)
11
63
5
57
1
48
4
54
45
3
51
Q.1.1 By completing the table below and then applying the relevant formulae, determine the line of best fit for this bivariate data set.
Do NOT change the units for the variables.
X
y
X2
xy
Ex=
Ey=
EX2
EXY=
Q.1.2 Estimate the number of units of the good that would have been produced last month by an employee with 8 years of experience.
Q.1.3 Using your calculator, determine the coefficient of correlation for the data set.
Interpret your answer.
Q.1.4 Compute the coefficient of determination for the data set.
Interpret your answer.
Chapter 3 Solutions
ELEMENTARY STATISTICS PKG. F13
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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