Statistics: The Art and Science of Learning from Data (4th Edition)
4th Edition
ISBN: 9780321997838
Author: Alan Agresti, Christine A. Franklin, Bernhard Klingenberg
Publisher: PEARSON
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Chapter 3.4, Problem 60PB
Age a confounder? A study observes that the subjects in the study who say they exercise regularly reported only half as many serious illnesses per year, on the average, as those who say they do not exercise regularly. One paragraph in the results section of an article about the study starts out, “We next analyzed whether age was a confounding variable in studying this association.”
- a. Explain what this sentence means and how age could potentially explain the association between exercising and illnesses.
- b. If age was not actually measured in the study and the researchers failed to consider its effects, could it be a confounding variable or a lurking variable? Explain the difference between a lurking variable and a confounding variable.
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Chapter 3 Solutions
Statistics: The Art and Science of Learning from Data (4th Edition)
Ch. 3.1 - Which is the response/explanatory variable? For...Ch. 3.1 - Sales and advertising Each month, the owner of...Ch. 3.1 - Does higher income make you happy? Every General...Ch. 3.1 - Diamonds The clarity and cut of a diamond are two...Ch. 3.1 - Alcohol and college students The Harvard School of...Ch. 3.1 - How to fight terrorism? A survey of 1000 adult...Ch. 3.1 - Heaven and hell Two questions on the General...Ch. 3.1 - Prob. 8PBCh. 3.1 - Gender gap in party ID In recent election years,...Ch. 3.1 - Use the GSS Go to the GSS website...
Ch. 3.2 - Used cars and direction of association For the 100...Ch. 3.2 - Broadband and GDP The Internet Use data file on...Ch. 3.2 - Prob. 13PBCh. 3.2 - Politics and newspaper reading For the FL Student...Ch. 3.2 - Prob. 15PBCh. 3.2 - Match the scatterplot with r Match the following...Ch. 3.2 - Prob. 17PBCh. 3.2 - Prob. 18PBCh. 3.2 - Prob. 19PBCh. 3.2 - Prob. 20PBCh. 3.2 - Prob. 21PBCh. 3.2 - Prob. 22PBCh. 3.2 - Prob. 23PBCh. 3.3 - Sketch plots of lines Identify the values of the...Ch. 3.3 - Prob. 25PBCh. 3.3 - Home selling prices The House Selling Prices FL...Ch. 3.3 - Prob. 27PBCh. 3.3 - Prob. 28PBCh. 3.3 - Prob. 29PBCh. 3.3 - Broadband subscribers and population The Internet...Ch. 3.3 - Prob. 31PBCh. 3.3 - Prob. 32PBCh. 3.3 - Regression between cereal sodium and sugar The...Ch. 3.3 - Prob. 34PBCh. 3.3 - Advertising and sales Each month, the owner of...Ch. 3.3 - Midtermfinal correlation For students who take...Ch. 3.3 - Predict final exam from midterm In an introductory...Ch. 3.3 - NL baseball Example 9 related y = team scoring...Ch. 3.3 - Study time and college GPA A graduate teaching...Ch. 3.3 - Oil and GDP An article in the September 16, 2006,...Ch. 3.3 - Mountain bikes revisited Is there a relationship...Ch. 3.3 - Mountain bike and suspension type Refer to the...Ch. 3.3 - Fuel Consumption Most cars are fuel efficient when...Ch. 3.4 - Extrapolating murder The SPSS figure shows the...Ch. 3.4 - Mens Olympic long jumps The Olympic winning mens...Ch. 3.4 - U.S. average annual temperatures Use the U.S....Ch. 3.4 - Murder and education Example 13 found the...Ch. 3.4 - Murder and poverty For Table 3.6, the regression...Ch. 3.4 - TV watching and the birth rate The figure shows...Ch. 3.4 - Looking for outliers Using software, analyze the...Ch. 3.4 - Regression between cereal sodium and sugar Let x =...Ch. 3.4 - Gestational period and life expectancy Does the...Ch. 3.4 - Antidrug campaigns An Associated Press story (June...Ch. 3.4 - Whats wrong with regression? Explain whats wrong...Ch. 3.4 - Education causes crime? The table shows a small...Ch. 3.4 - Death penalty and race The table shows results of...Ch. 3.4 - NAEP scores Eighth-grade math scores on the...Ch. 3.4 - Age a confounder? A study observes that the...Ch. 3 - Choose explanatory and response For the following...Ch. 3 - Graphing data For each case in the previous...Ch. 3 - Life after death for males and females In a recent...Ch. 3 - God and happiness Go to the GSS website...Ch. 3 - Degrees and income The mean annual salaries earned...Ch. 3 - Bacteria in ground turkey Consumer Reports...Ch. 3 - Women managers in the work force The following...Ch. 3 - RateMyProfessor.com The website RateMyProfessors....Ch. 3 - Women in government and economic life The OECD...Ch. 3 - African droughts and dust Is there a relationship...Ch. 3 - Crime rate and urbanization For the data in...Ch. 3 - Gestational period and life expectancy revisited...Ch. 3 - Height and paycheck The headline of an article in...Ch. 3 - Predicting college GPA An admissions officer...Ch. 3 - College GPA = high school GPA Refer to the...Ch. 3 - Whats a college degree worth? In 2002, a census...Ch. 3 - Care Weight and gas hogs: The table shows a short...Ch. 3 - Predicting Internet use from cell phone use We now...Ch. 3 - Income depends on education? For a study of...Ch. 3 - Fertility and GDP Refer to the Human Development...Ch. 3 - Women working and birth rate Using data from...Ch. 3 - Education and income The regression equation for a...Ch. 3 - Income in euros Refer to the previous exercise....Ch. 3 - Changing units for cereal data Refer to the Cereal...Ch. 3 - Murder and single-parent families For Table 3.6 on...Ch. 3 - Violent crime and college education For the U.S....Ch. 3 - Violent crime and high school education Repeat the...Ch. 3 - Crime and urbanization For the U.S. Statewide...Ch. 3 - High school graduation rates and health insurance...Ch. 3 - Womens Olympic high jumps Example 11 discussed how...Ch. 3 - Income and height A survey of adults revealed a...Ch. 3 - More TV watching goes with fewer babies? For...Ch. 3 - More sleep causes death? An Associated Press story...Ch. 3 - Ask Marilyn Marilyn vos Savant writes a column for...Ch. 3 - Time studying and GPA Is there a relationship...Ch. 3 - Warming in Newnan, Georgia Access the Newnan GA...Ch. 3 - Fluoride and AIDS An Associated Press story...Ch. 3 - Fish fights Alzheimers An AP story (July 22, 2003)...Ch. 3 - Dogs make you healthier A study published in the...Ch. 3 - Multiple choice: Correlate GPA and GRE In a study...Ch. 3 - Multiple choice: Properties of r Which of the...Ch. 3 - Multiple choice: Interpreting r One can interpret...Ch. 3 - Multiple choice: Correct statement about r Which...Ch. 3 - Multiple choice: Describing association between...Ch. 3 - Multiple choice: Slope and correlation The slope...Ch. 3 - Multiple choice: Interpretation of r2 An r2...Ch. 3 - True or false The variables y = annual income...Ch. 3 - Correlation doesnt depend on units Suppose you...Ch. 3 - When correlation = slope Consider the formula...Ch. 3 - Center of the data Consider the formula a=ybx for...Ch. 3 - Final exam regresses toward mean of midterm Let y...Ch. 3 - Activity: Guess the correlation The Guess the...
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