Introductory Statistics (2nd Edition)
2nd Edition
ISBN: 9780321978271
Author: Robert Gould, Colleen N. Ryan
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 1, Problem 62CRE
Brief Exercise and Diabetes As part of a study, sixteen young men performed high-intensity exercise that totaled only 15 minute in two-week period. At the end of two weeks, several (but not all) tests for diabetes, such as an insulin sensitivity test, showed improvement. Do these results indicate that brief, high-intensity exercise causes an improvement in markers for diabetes? What essential component of both controlled experiments and observational studies is missing from this study?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
A study is designed to test whether there is a difference in mean daily calcium intake in adults with normal bone density, adults with osteopenia (a low bone density which may lead to osteoporosis) and adults with osteoporosis. Adults 60 years of age with normal bone density, osteopenia and osteoporosis are selected at random from hospital records and invited to participate in the study. Each participant's daily calcium intake is measured based on reported food intake and supplements. The data are shown below.
Is there a statistically significant difference in mean calcium intake in patients with normal bone density as compared to patients with osteopenia and osteoporosis?
Studies have suggested that alcohol abuse and disorders are found to be more prevalent during early adulthood than in any other age group, with about 9% of young adults (age 18 to 29 years) meeting the criteria to be labeled as alcoholic. In addition, surveys have shown that college students tend to drink more than their peers who do not attend college.
You want to test to see if there are differences in excessive alcohol use in young adults that attend college versus those who do not, so you surveyed 405 young adults, age 19 to 22, about their alcohol use by asking the question, "Have you consumed alcohol to the point of intoxication at least once within the past month?" with the following results.
Young Adults Attending College
Young Adults Not Attending College
n1 = 255
n2 = 150
y1 = 96
said "yes"
y2 = 44
said "yes"
p̂1 =
96
255
p̂2 =
44
150
(a)
Calculate the test statistic. (Round your answer to two decimal places.)
(b)
If
H0:…
Could it be that smoking actually increases survival rates among women? The accompanying data represent the 20-year survival status and smoking status of
1334 women who participated in a 20-year cohort study. Complete parts (a) through (e).
Chapter 1 Solutions
Introductory Statistics (2nd Edition)
Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...
Ch. 1 - SECTION EXERCISES Brain Size (Example 2) In 1991,...Ch. 1 - SECTION EXERCISES Students’ Ages The accompanying...Ch. 1 - Snacks Emmanuel, a student at a Los Angeles high...Ch. 1 - Movies A sample of students were questioned to...Ch. 1 - SECTION EXERCISES Older Siblings (Example 3) At a...Ch. 1 - SECTION EXERCISES College Students working at a...Ch. 1 - Finding and Using Percentages a. A statistics...Ch. 1 - Finding and Using Percentages a. A hospital...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES The data in the Table 1A were...Ch. 1 - SECTION EXERCISES Two-Way Table from Data The...Ch. 1 - SECTION EXERCISES Two-way Table from Data Make a...Ch. 1 - SECTION EXERCISES Population Prediction The 2009...Ch. 1 - SECTION EXERCISES 2007 Population The 2009 World...Ch. 1 - Living with AIDS The table gives the number of...Ch. 1 - Population Density The accompanying table gives...Ch. 1 - Marriage rates the number of married people in the...Ch. 1 - Births and Deaths the following information about...Ch. 1 - Course Enrollment Rates (Example 5 ) two sections...Ch. 1 - Pedestrian fatalities In 2008, the National...Ch. 1 - Prob. 31SECh. 1 - Records of patients who have had broken ankles are...Ch. 1 - For Exercises 1.39 through 1.44, indicate whether...Ch. 1 - For Exercises 1.39 through 1.44, indicate whether...Ch. 1 - For Exercises 1.39 through 1.44, indicate whether...Ch. 1 - For Exercises 1.39 through 1.44, indicate whether...Ch. 1 - A researcher was interested in the effect of...Ch. 1 - A researcher was interested in the effect of...Ch. 1 - Effects of Tutoring on Math Grades (Example 8) A...Ch. 1 - Treating Depression A doctor who believes strongly...Ch. 1 - Early Tonsillectomy for Children (Example 6 )...Ch. 1 - Pneumonia Vaccine for Young Children A study...Ch. 1 - Copper Bracelets (Example 7 ) Some people believe...Ch. 1 - Weight Loss Study A group of overweight people are...Ch. 1 - Do Pesticides Cause Parkinson's Disease? A study...Ch. 1 - Breast Cancer Two drugs were tested to see whether...Ch. 1 - Flu Vaccine In the fall of 2004, there was a...Ch. 1 - Effect of Confederates on Compliance A study was...Ch. 1 - Vitamin C and Allergies (Example 8 ) Posted at the...Ch. 1 - Does Overeating Reduce Brain Function? The Harvard...Ch. 1 - Effects of Light Exposure (Example 9) A study...Ch. 1 - Scared Straight The idea of sending delinquents to...Ch. 1 - Obesity and Marital Status A 2009 study analyzed...Ch. 1 - Prob. 54CRECh. 1 - Probation a statistics student conducted a study...Ch. 1 - Scorpion Antivenom A study was done on children (6...Ch. 1 - Writing: Vitamin D Describe the design of a...Ch. 1 - Writing: Strokes People who have had strokes are...Ch. 1 - Medicaid Expansion Medicaid is a program...Ch. 1 - HIV-1 and HIV-2 Does infection with HIV-2 slow the...Ch. 1 - Death Row and Head Trauma A study conducted by...Ch. 1 - Brief Exercise and Diabetes As part of a study,...
Knowledge Booster
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.Similar questions
- What is an experiment? Give two examples.arrow_forwardIn an observational study it was found that people who had received the flu shot this year had better blood pressure readings, on average, than people who did not. Can it be claimed that the flu shot is the cause of the lower overall blood pressure? Why or why not?arrow_forwardAs men age, their testosterone levels gradually decrease. This may cause a reduction in energy, an increase in fat, and other undesirable changes. Do testosterone supplements reverse some of these effects? A study in the Netherlands assigned 237 men aged 60 to 80 with low or low-normal testosterone levels to either a testosterone supplement or a placebo. Why is it necessary to include a control group in this experiment? Every experiment needs a control group in order to make proper comparisons between treatments. A control group is necessary to balance the effects of other variables among the treatment groups. A control group is necessary so any differences in the effects of the treatments can be distinguished from chance differences between the groups. A control group helps avoid confounding and reduces variability in the response variable. A control group is used to provide a baseline for comparing the effects of other treatments.arrow_forward
- The Framingham Heart Study was a longitudinal cohort study of 5000+ men and women. One outcome of interest was fasting glucose levels. Glucose levels were categorized into three different categories: Glucose Levels -Diabetes (glucose > 126), -Impaired Fasting Glucose (glucose 100-125), -Normal Glucose Several possible risk factors were also recorded: Risk Factors -Sex -Age -BMI (normal weight, overweight, obese) -Genetics To determine if each possible risk factor is related to glucose levels, researchers need to use an appropriate hypothesis test. Use Table 7-50 on page 161 of the textbook to select the correct test from the gray box above. What test would be used to assess whether the different sexes (male and female) have the same proportions of the different glucose levels? What test would be used to assess whether the different glucose levels have the same mean age? What test would be used to assess whether the different categories of BMI…arrow_forwardLabor Day was created by the U.S. labor movement over 100 years ago. It was subsequently adopted by most states as an official holiday. In a poll by Gallup, 1000 randomly selected adults were asked whether they approve of labor unions; 650 said yes. In 1936, about 72% of Americans approved of labor unions. At a 5% level of significance, do the data provide sufficient evidence to conclude that the percentage of Americans who approve of labor unions now has decreased since 1936? Solve using the critical-value approach. a. Define the parameter we are testing and setup a hypothesis test to see if less than 72% of Americans approve of labor unions currently. b. Calculate the test statistics for this hypothesis test. c. What is the critical value for this hypothesis test?arrow_forwardSex and violence. Does the content of a television pro-gram affect viewers’ memory of the products advertised in commercials? Design an experiment to compare theability of viewers to recall brand names of items featuredin commercials during programs with violent content,sexual content, or neutral content.arrow_forward
- 6. Binge-watching a television show might not be the best way to enjoy a television series (Horvath et al., 2017). Participants in an experiment were in a group that either watched an entire tv series during daily one-hour sessions or watched all the episodes during a single binge session. Participants were asked to rate their enjoyment of the t.v. series on a scale of 0-100. Data like those observed by the author are listed below: Binge-watched 87 Daily-watched 84 71 100 73 87 86 97 78 92 a. Is there a difference in the level of enjoyment based on whether the series was binge-watched or watched on a daily basis? Use a two-tailed test at the a = 0.05 level of significance? b. Do the data analysis in SPSS in addition to your hand calculations. Attach a printout of your results.arrow_forwardThe Human Resources Department is studying absenteeism with employees. They have noticed an unacceptable level of absenteeism that is believed to be related to the general health of the employees. Twelve months ago, a fitness program for employees was started at the company. To evaluate the program, a random sample of eight participants were studied before the fitness program began and the same eight participants were studied twelve months later. The Human Resources Department believes the number of absences should change over the twelve months. Before After Difference Employee 1. What is dbar? 2. What is tcrit? 3. What is at? 4. What is pvalue? 1 5. What is decision? 6 5 2 6 2 four decimal places four decimal places 3 four decimal places 7 1 4 At the 5% significance level, answer the following questions using the following information: Ho: mu d = 0 Ha: mud #0 7 3 5 4 3 6 3 6 7 5 3 8 6 7 standard deviation of sample = 2.92arrow_forwardResearchers have observed that high school students who watched educational television programs as young children tend to have higher grades than their peers who did not watch educational television. Is this an observational study or a controlled experiment? Explain why.arrow_forward
- Social functioning is the ability for an individual to interact or adapt in a normal or usual way in social environments. Albert et al. (2007) asked if relatives of patients with OCD are as healthy as those in general healthy populations. They measured the social functioning of relatives using a 36-item survey with scores ranging from 0 (worst possible health) to 100 (best possible health). The mean score for the general healthy population was 77.43. Using the sample data, test whether there was a difference. Scores: 20, 60, 48, 92, 50, 82, 48, 90, 30, 68, 43, 54, 60, 62, 94, 67, 63, 85 State hypotheses 2. Set the criteria using α= 0.05 3. Calculate t 4. What should you conclude?arrow_forwardHow much does novelty influence the choice of vacation destination? Petrick (2002) reports results of a survey in which 448 golf vacationers completed a postal survey after their stay at a golf resort. The questionnaire included thirteen items on aspects of 'novelty' regarding golf vacations: four assessing 'thrill', and three each on 'change from routine', 'boredom alleviation', and 'surprise'. Each item required a response on a Likert scale from 1 to 5, where a higher number indicated a greater novelty value. Certain research hypotheses related to how factors of novelty would be predicted by four explanatory variables: the number of golf rounds played per year (X1), the lifetime total number of golf vacations taken (X2), the number of years playing golf (X3), and the mean golf score (X4). Part a)We consider first the response variable of the total questionnaire score on the 'change from routine' responses (Y)(Y). A model of the form Y=β0+β1X1+β2X2+β3X3+β4X4+ε is fitted to the data,…arrow_forward"Bullying," according to noted expert Dan Olweus, "poisons the educational environment and affects the learning of every child." Bullying and victimization are evident as early as preschool, with the problem peaking in middle school. Suppose you are interested in the emotional well-being of not only the victims but also bystanders, bullies, and those who bully but who are also victims (bully-victims). You decide to measure depression in a group of victims and a group of bully-victims using a 26-item, 3-point depression scale. Assume scores on the depression scale are normally distributed and that the variances of the depression scores are the same among victims and bully-victims. The group of 25 victims scored an average of 25.3 with a sample standard deviation of 9 on the depression scale. The group of 23 bully-victims scored an average of 20.5 with a sample standard deviation of 8 on the same scale. You do not have any presupposed assumptions about whether victims or bully-victims…arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt
- College Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning
Holt Mcdougal Larson Pre-algebra: Student Edition...
Algebra
ISBN:9780547587776
Author:HOLT MCDOUGAL
Publisher:HOLT MCDOUGAL
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Big Ideas Math A Bridge To Success Algebra 1: Stu...
Algebra
ISBN:9781680331141
Author:HOUGHTON MIFFLIN HARCOURT
Publisher:Houghton Mifflin Harcourt
College Algebra (MindTap Course List)
Algebra
ISBN:9781305652231
Author:R. David Gustafson, Jeff Hughes
Publisher:Cengage Learning
Hypothesis Testing - Solving Problems With Proportions; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=76VruarGn2Q;License: Standard YouTube License, CC-BY
Hypothesis Testing and Confidence Intervals (FRM Part 1 – Book 2 – Chapter 5); Author: Analystprep;https://www.youtube.com/watch?v=vth3yZIUlGQ;License: Standard YouTube License, CC-BY