Introduction To Statistics And Data Analysis
6th Edition
ISBN: 9781337793612
Author: PECK, Roxy.
Publisher: Cengage Learning,
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 11.1, Problem 4E
Use the information in the previous exercise to answer the following questions.
- a. Construct a 90% confidence
interval estimate of the difference in mean Flesch reading ease score for health-related pages on Wikipedia and health-related pages on WebMD. - b. What does this confidence interval imply about the readability of health-related information from these two sources? Is this consistent with the conclusion in the hypothesis test of the previous exercise?
Many people now tum to the Internet to get information on health-related topics. The paper “An Examination of Health, Medical and Nutritional Information on the Internet: A Comparative Study of Wikipedia, WebMD and the Mayo Clinic Websites” (The International Journal of Communication and Health [2015]: 30–38) used Flesch reading ease scores (a measure of reading difficulty based on factors such as sentence length and number of syllables in the words used) to score pages on Wikipedia and on WebMD. Higher Flesch scores correspond to more difficult reading levels. The paper reported that for a representative sample of health-related pages on Wikipedia, the mean Flesch score was 26.7 and the standard deviation of the Flesch scores was 14.1. For a representative sample of pages from WebMD, the mean score was 43.9 and the standard deviation was 19.4. Suppose that these means and standard deviations were based on samples of 40 pages from each site. Is there convincing evidence that the mean reading level for health-related pages differs for Wikipedia and WebMD? Test the relevant hypotheses using a significance level of 0.05.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
For each of the following questions, indicate whether it is best assessed by using a confidence interval or a hypothesis test or whether statistical inference is not relevant to answer it. (answer all please!!)
Do a majority of adults riding a bicycle wear a helmet?
On average, how many more minutes do ladies spend in the restroom than men?
Is the median Exam 1 score for STA 270 students in section 10 any different from that of STA 270 students in section 11?
What is the average daily calorie intake of 20-year-old males?
In 2010, what percent of the US Senate voted to confirm Elena Kagan as a member of the Supreme Court?
An epidemiologist is worried about the prevalence of the flu in East Vancouver and the potential shortage of vaccines for the area. She will need to provide a recommendation for how to allocate the vaccines appropriately across the city. She takes a simple random sample of 339 people living in East Vancouver and finds that 40 have recently had the flu.
For each of the following statements, specify whether the statement is a correct interpretation of the 95% confidence interval for the true proportion of East Vancouver residents who have recently had the flu.
A. 11.80% (40/339) of East Vancouver residents have recently had the flu. ? true false
B. There is a 95% probability that the true proportion of East Vancouver residents who have recently had the flu equals 40/339. ? true false
C. If another random sample of 339 East Vancouver residents is drawn, there is a 95% probability that the sample proportion of East Vancouver residents who have recently had the flu equals 40/339. ?…
The business manager of a local health clinic is interested in estimating the difference between the fees for extended office visits in her center and the fees of a newly opened group practice. She gathered the following information regarding the two offices.
Health Clinic Group Practice
Sample size 50 visits 45 visits
Sample mean $21 $19
Population Standard deviation $2.75 $3.00
a. What is your conclusion? Use a= 0.05.
b. Develop a 95% confidence interval estimate for the difference between the average fees of the two offices.
Chapter 11 Solutions
Introduction To Statistics And Data Analysis
Ch. 11.1 - Consider two populations for which 1 = 30, 1 = 2,...Ch. 11.1 - An individual can take either a scenic route to...Ch. 11.1 - Many people now tum to the Internet to get...Ch. 11.1 - Use the information in the previous exercise to...Ch. 11.1 - The article Plugged In, but Tuned Out (USA TODAY,...Ch. 11.1 - The National Sleep Foundation surveyed...Ch. 11.1 - The report referenced in the previous exercise...Ch. 11.1 - The paper If Its Hard to Read, Its Hard to Do...Ch. 11.1 - The paper Facebook Use and Academic Performance...Ch. 11.1 - Use the information in the previous exercise to...
Ch. 11.1 - Prob. 11ECh. 11.1 - The paper Mood Food: Chocolate and Depressive...Ch. 11.1 - The authors of the paper Influence of Biofeedback...Ch. 11.1 - Example 11.1 looked at a study comparing students...Ch. 11.1 - Internet addiction has been described as excessive...Ch. 11.1 - The paper Does the Color of the Mug Influence the...Ch. 11.1 - A newspaper story headline reads Gender Plays Part...Ch. 11.1 - The authors of the paper The Empowering (Super)...Ch. 11.1 - Fumonisins are environmental toxins produced by a...Ch. 11.1 - A researcher at the Medical College of Virginia...Ch. 11.1 - Do certain behaviors result in a severe drain on...Ch. 11.2 - Suppose that you were interested in investigating...Ch. 11.2 - Many runners believe that listening to music while...Ch. 11.2 - The study described in the previous exercise also...Ch. 11.2 - In Exercise 11.23, a hypothesis test leads to the...Ch. 11.2 - The article Puppy Love? Its Real, Study Says (USA...Ch. 11.2 - The authors of the paper Concordance of...Ch. 11.2 - The paper referenced in the previous exercise also...Ch. 11.2 - The paper Driving Performance While Using a Mobile...Ch. 11.2 - The paper referenced in the previous exercise also...Ch. 11.2 - Use the information given in the previous exercise...Ch. 11.2 - To determine if chocolate milk was as effective as...Ch. 11.2 - The humorous paper Will Humans Swim Faster or...Ch. 11.2 - The study described in the paper Marketing Actions...Ch. 11.2 - Head movement evaluations are important because...Ch. 11.2 - The paper Less Air Pollution Leads to Rapid...Ch. 11.2 - The paper The Truth About Lying in Online Dating...Ch. 11.2 - The paper Quantitative Assessment of Glenohumeral...Ch. 11.2 - Two proposed computer mouse designs were compared...Ch. 11.2 - The authors of the paper Ultrasound Techniques...Ch. 11.3 - Some people seem to believe that you can fix...Ch. 11.3 - The report titled Digital Democracy Survey (2016,...Ch. 11.3 - After the 2010 earthquake in Haiti, many...Ch. 11.3 - The article Most Women Oppose Having to Register...Ch. 11.3 - The article referenced in the previous exercise...Ch. 11.3 - The report Audience Insights: Communicating to...Ch. 11.3 - According to the U.S. Census Bureau, the...Ch. 11.3 - The article Fish Oil Staves Off Schizophrenia (USA...Ch. 11.3 - The report Young People Living on the Edge...Ch. 11.3 - The report Raising Kids and Running a Household:...Ch. 11.3 - The Bureau of Labor Statistics...Ch. 11.3 - The Bureau of Labor Statistics report referenced...Ch. 11.3 - The report The New Food Fights: U.S. Public...Ch. 11.3 - A survey of high school students is described in...Ch. 11.3 - The article Spray Flu Vaccine May Work Better Than...Ch. 11.3 - The following quote is from the article Canadians...Ch. 11.3 - A Harris Poll press release dated November 1,...Ch. 11.3 - Women diagnosed with breast cancer whose tumors...Ch. 11.3 - Gallup surveyed adult Americans about their...Ch. 11.4 - The paper The Psychological Consequences of Money...Ch. 11.4 - An experiment to determine if an online...Ch. 11.4 - The paper Ready or Not? Criteria for Marriage...Ch. 11.5 - Use the information given in the previous exercise...Ch. 11.5 - Prob. 66ECh. 11.5 - Prob. 68ECh. 11.5 - Prob. 70ECh. 11.6 - The article Rapid Evolutionary Response to a...Ch. 11.6 - Prob. 72ECh. 11.6 - Prob. 74ECh. 11.6 - Prob. 75ECh. 11.6 - As part of a study described in the report I Cant...Ch. 11.6 - Prob. 78ECh. 11 - A deficiency of the trace element selenium in the...Ch. 11 - Prob. 80CRCh. 11 - In a study of a proposed treatment for diabetes...Ch. 11 - When a surgeon repairs injuries, sutures (stitched...Ch. 11 - Prob. 83CRCh. 11 - In a study of memory recall, eight students from a...Ch. 11 - As part of a study to determine the effects of...Ch. 11 - The article Truth and DARE: Tracking Drug...Ch. 11 - The article Softball Sliding Injuries (American...Ch. 11 - Wayne Gretzky was one of ice hockeys most prolific...Ch. 11 - Heres one to sink your teeth into: The authors of...Ch. 11 - Dentists make many people nervous. To see whether...Ch. 11 - Both surface soil and subsoil specimens were taken...
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
- A research group studying cell phone habits asked the question “Do you ever use your cell phone to make a payment at a convenience store?” to people selected from two random samples of cell phone users. One sample consisted of older adults, ages 35 years and older, and the other sample consisted of younger adults, ages 18 years to 34 years. The proportion of people who answered yes in each sample was used to create a 95 percent confidence interval of (0.097,0.125)(0.097,0.125) to estimate the difference (younger minus older) between the population proportions of people who would answer yes to the question. Which of the following is the best description of what is meant by 95 percent confidence? In repeated random sampling with the same sample size, approximately 95% of the sample proportions from the younger group will be between 0.097 and 0.125 greater than the sample proportion from the older group. A In repeated random sampling with the same sample size,…arrow_forwardThe following data were collected in a clinical trial to compare a new drug to a placebo for its effectiveness in lowering total serum cholesterol. New Drug (n=75) Placebo (n=75) Total Sample (n=150) Mean (SD) Total Serum Cholesterol 182.0 (24.5) 206.3 (21.8) 194.15 (23.2) % Patients with Total Cholesterol < 200 78.0% 65.0% 71.5% Generate the 95% confidence interval for the difference in mean total cholesterol levels between treatments Generate a 95% confidence interval for the difference in proportions of all patients with total cholesterol < 200. How many patients would be required to detect the difference in proportions observed in the current study with 80% power. A new investigation will be enrolling subjects to demonstrate the efficacy of the drug in individuals with high cholesterol at an early age. A two-sided test is planned at α = 0.05arrow_forward1. A recent survey showed that from a sample of 500 packages delivered by a Postal Service, 480were delivered on time. a) Construct a 95% confidence interval for the proportion of all packages that are deliveredon time by the Postal Service.arrow_forward
- The following data were collected in a clinical trial to compare a new drug to a placebo for its effectiveness in lowering total serum cholesterol. New Drug (n=75) Placebo (n=75) Total Sample (n=150) Mean (SD) Total Serum Cholesterol 182.0 (24.5) 206.3 (21.8) 194.15 (23.2) % Patients with Total Cholesterol < 200 78.0% 65.0% 71.5% 1. Generate the 95% confidence interval for the difference in mean total cholesterol levels between treatments 2. Generate a 95% confidence interval for the difference in proportions of all patients with total cholesterol < 200.arrow_forwardAfter reporting the results from a formal hypothesis test, it is often likely that statisticians will report a confidence interval in order to indicate that a null value is present, indicating a significant response . True Falsearrow_forwardTo construct a confidence interval for each of the following quantities, say whether it would be better to use paired samples or independent samples. a) The mean difference in weight loss between people on two different diets. b) The mean difference in weight before and after eight weeks on a certain diet. c) The mean difference in standardized test scores between the first and second attempt at the test. d) The mean difference in test scores between students taught by different methodsarrow_forward
- In a recent questionnaire about homeownership, a random sample of 545 homeowners were asked about fixed and adjustable-rate mortgages, and 268 reported that they have an adjustable-rate mortgage. What value of z should be used to calculate a confidence interval with a 95% confidence level? z0.10 z0.05 z0.025 z0.01 z0.005 1.282 1.645 1.960 2.326 2.576arrow_forward1. Consider the following results for independent samples taken from two populations a. What is the point estimate of the difference between the two population proportions?b. Develop a 90% confidence interval for the difference between the two population proportions.c. Develop a 95% confidence interval for the difference between the two population proportionsarrow_forwardApply the Q-Test to the following data to determine whether the outlying result should be retained or rejected at 95% confidence level 7.295, 7.284, 7.388, 7.292arrow_forward
- Which of the following confidence levels and significance levels are appropriate for using a confidence interval approach to hypothesis testing? Confidence Level = 99% and α = 0.01 Confidence Level = 95% and α = 0.01 Confidence Level = 95% and α = 0.5 Confidence Level = 90% and α = 0.01arrow_forwardThe International Nanny Association (INA) reports that in a sample of 928 in- home child care providers (nannies), 128 have passed the INA Nanny Credential Exam (2014 International Nanny Association Salary and Benefits Survey). A. Use Wilson’s adjustment to find a 95% confidence interval for the true proportion of all nannies who have passed the INA certification exam. B. We want to decide whether the proportion of who passed the INA certification exam exceeds than .12 answer both a and b.arrow_forwardA recent survey of cell phone users indicated that 56 percent of the respondents prefer to use cell phones for texting rather than for making phone calls. A 95 percent confidence interval for the estimate of all cell phone users who prefer to use cell phones for texting has a margin of error of 3 percent. Assume all conditions for inference have been met. Based on the confidence interval, which of the following claims is supported? Select A, B, C, or D Less than half of all people prefer texting. A More than half of all people prefer texting. B At least 60 percent of all people prefer texting. C At least 75 percent of all people prefer texting. D At least 95 percent of all people prefer texting. Earrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Hypothesis Testing using Confidence Interval Approach; Author: BUM2413 Applied Statistics UMP;https://www.youtube.com/watch?v=Hq1l3e9pLyY;License: Standard YouTube License, CC-BY
Hypothesis Testing - Difference of Two Means - Student's -Distribution & Normal Distribution; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=UcZwyzwWU7o;License: Standard Youtube License