Richard D. De Veaux, Paul F. Velleman, David E. Bock
ISBN #9780321986498
4th Edition
1,406 Questions
Homework Questions
Stats Data and Models is a comprehensive guide that takes readers on a journey through the core concepts and practical tools of statistical analysis. The book begins by demystifying data through exploratory analysis and gradually builds into more complex topics like regression, experimental design, and probability models. It methodically introduces key techniques—from visualizing data with histograms and boxplots to performing hypothesis tests and ANOVA—each presented as essential “characters” in the narrative of data analysis. Overall, the text uniquely blends foundational theory with practical applications, empowering readers to make informed decisions and draw meaningful conclusions from varied datasets.
Chapter 1
Stats Starts Here
Chapter 2
Displaying and Describing Categorical Data
Chapter 3
Displaying and Summarizing Quantitative Data
Chapter 4
Understanding and Comparing Distributions
Chapter 5
The Standard Deviation as a Ruler and the Normal Model
Chapter 6
Scatterplots, Association, and Correlation
Chapter 7
Linear Regression
Chapter 8
Regression Wisdom
Chapter 9
Re-expressing Data: Get It Straight
Chapter 10
Understanding Randomness
Chapter 11
Sample Surveys
Chapter 12
Experiments and Observational Studies
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Chapter 13
From Randomness to Probability
Chapter 14
Probability Rules
Chapter 15
Random Variables
Chapter 16
Probability Models
Chapter 17
Sampling Distribution Models
Chapter 18
Confidence Intervals for Proportions
Chapter 19
Testing Hypotheses About Proportions
Chapter 20
Inferences About Means
Chapter 21
More About Tests and Intervals
Chapter 22
Comparing Groups
Chapter 23
Paired Samples and Blocks
Chapter 24
Comparing Counts
Chapter 25
Inferences for Regression
Chapter 26
Analysis of Variance
Chapter 27
Multifactor Analysis of Variance
Chapter 28
Multiple Regression
Problem 1
Are good grades in high school associated with family togetherness? A random sample of 142 high school students was asked how many meals per week their families ate together. Their responses produced a mean of 3.78 meals per week, with a standard deviation of $2.2 .$ Researchers then matched these responses against the students' grade point averages (GPAs). The scatterplot appeared to be reasonably linear, so they created a line of regression. No apparent pattern emerged in the residuals plot. The equation of the line was $\widehat{G P A}=2.73+0.11$ Meals. a) Interpret the $y$ -intercept in this context. b) Interpret the slope in this context. c) What was the mean GPA for these students? d) If a student in this study had a negative residual, what did that mean? e) Upon hearing of this study, a counselor recommended that parents who want to improve the grades their children get should get the family to eat together more often. Do you agree with this interpretation? Explain.
James Kiss Numerade Educator
Problem 2
Association Suppose you were to collect data for each pair of variables. You want to make a scatterplot. Which variable would you use as the explanatory variable and which as the response variable? Why? What would you expect to see in the scatterplot? Discuss the likely direction, form, and strength. a) Apples: weight in grams, weight in ounces b) Apples: circumference (inches), weight (ounces) c) College freshmen: shoe size, grade point average d) Gasoline: number of miles you drove since filling up, gallons remaining in your tank
Sheryl Ezze Numerade Educator
Problem 3
Nonoccupant fatalities The frequencies of traffic fatalities of nonoccupants of vehicles are shown in the following bar chart. Change this to a bar chart of relative frequencies.
Rashmi Sinha Numerade Educator
Problem 4
If false, explain briefly. a) Some of the residuals from a least squares linear model will be positive and some will be negative. b) Least Squares means that some of the squares of the residuals are minimized. c) We write $\hat{y}$ to denote the predicted values and $y$ to denote the observed values.
Problem 5
Gallup regularly conducts a poll asking people to imagine a ladder with 10 rungs. Rung 0 represents the worst possible life and rung 10 represents the best possible life. Respondents are asked what rung they would say they are on. Responses are classified as "Thriving" (standing on rung 7 or higher, and expecting to be on rung 8 or higher five years from now), "Suffering" (standing on rung 4 or lower and expecting to be on rung 4 or lower 5 years from now), or "Struggling" (not thriving or suffering). The poll for November $22-25,2011,$ found $4 \%$ of respondents to be suffering. The polls all use a sample size of approximately 1500 people. (www.gallup .com/poll/152033/Fewer-Americans-Thriving-2011- 2010.aspx) a) Explain the meaning of $" \hat{p}=0.04$ " in the context of this situation. b) Calculate the standard error of $\hat{p}$. c) Explain what this standard error means in the context of this situation.
Problem 6
Grocery shopping Many grocery store chains offer customers a card they can scan when they check out and offer discounts to people who do so. To get the card, customers must give information, including a mailing address and e-mail address. The actual purpose is not to reward loyal customers but to gather data. What data do these cards allow stores to gather, and why would they want that data?
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