Introduction to Statistics and Data Analysis
5th Edition
ISBN: 9781305445963
Author: PECK
Publisher: Cengage
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Textbook Question
Chapter 11.1, Problem 9E
Is injecting medical cement effective in reducing pain for people who have suffered fractured vertebrae? The paper “A Randomized Trial of Vertebroplasty for Osteoporotic Spinal Fractures” (New England Journal of Medicine [2009]: 569-578) describes an experiment to compare patients who underwent vertebroplasty (the injection of cement) to patients in a placebo group who underwent a fake procedure in which no cement was actually injected. Because the placebo procedure was similar to the vertebroplasty procedure except for the actual injection of cement, patients participating in the experiment were not aware of which treatment they received.
All patients were asked to rate their pain at three different times—3 days, 14 days, and 1 month after the procedure. Summary statistics are given in the accompanying table.
- a. Briefly explain why the researchers may have chosen to include a placebo group that underwent a fake, procedure rather than just comparing the vertebroplasty group to a group of patients who did not receive any treatment.
- b. Construct and interpret a 95% confidence interval for the difference in
mean pain intensity 3 days after treatment for the vertebroplasty treatment and the fake treatment. (Hint: See Example 11.4.) - c. Construct and interpret 95% confidence intervals for the difference in mean pain intensity at 14 days and at 1 month after treatment.
- d. Based on the confidence intervals from Parts (b) and (c), comment on the effectiveness of injecting cement as a way of reducing pain for those with fractured vertebrae.
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Exercise 6-6 (Algo) (LO6-3)
The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience.
Admissions
Probability
1,100
0.5
1,400
0.4
1,300
0.1
Click here for the Excel Data File
Required:
What is the expected number of admissions for the fall semester?
Compute the variance and the standard deviation of the number of admissions.
Note: Round your standard deviation to 2 decimal places.
1. Find the mean of the x-values (x-bar)
and the mean of the y-values (y-bar) and write/label each here:
2. Label the second row in the table using proper notation; then, complete the table. In the fifth and sixth
columns, show the 'products' of what you're multiplying, as well as the answers.
X
y
x minus x-bar y minus y-bar (x minus x-bar)(y minus y-bar)
(x minus x-bar)^2
xy
16
20
34
4-2
5 2
3. Write the sums that represents Sxx and Sxy in the table, at the bottom of their respective columns.
4. Find the slope of the Regression line: bi
=
(simplify your answer)
5. Find the y-intercept of the Regression line, and then write the equation of the Regression line.
Show your work. Then, BOX your final answer. Express your line as "y-hat equals...
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 - Prob. 3ECh. 11.1 - Prob. 4ECh. 11.1 - The article Plugged In, but Tuned Out (USA TODAY,...Ch. 11.1 - Prob. 6ECh. 11.1 - Prob. 7ECh. 11.1 - The paper If Its Hard to Read, Its Hard to Do...Ch. 11.1 - Is injecting medical cement effective in reducing...Ch. 11.1 - Prob. 10E
Ch. 11.1 - Prob. 11ECh. 11.1 - The paper Mood Food: Chocolate and Depressive...Ch. 11.1 - Prob. 13ECh. 11.1 - Example 11.1 looked at a study comparing students...Ch. 11.1 - Prob. 15ECh. 11.1 - Prob. 16ECh. 11.1 - A newspaper story headline reads Gender Plays Part...Ch. 11.1 - Prob. 18ECh. 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 - Head movement evaluations are important because...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 - Prob. 27ECh. 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 - Prob. 30ECh. 11.2 - Prob. 31ECh. 11.2 - The paper Quantitative Assessment of Glenohumeral...Ch. 11.2 - Two proposed computer mouse designs were compared...Ch. 11.2 - Prob. 34ECh. 11.2 - Prob. 35ECh. 11.2 - The authors of the paper Ultrasound Techniques...Ch. 11.3 - Some people seem to believe that you can fix...Ch. 11.3 - Prob. 38ECh. 11.3 - After the 2010 earthquake in Haiti, many...Ch. 11.3 - Prob. 40ECh. 11.3 - The report Audience Insights: Communicating to...Ch. 11.3 - Prob. 42ECh. 11.3 - Prob. 43ECh. 11.3 - Prob. 44ECh. 11.3 - The article Fish Oil Staves Off Schizophrenia (USA...Ch. 11.3 - The report Young People Living on the Edge...Ch. 11.3 - Prob. 47ECh. 11.3 - Prob. 48ECh. 11.3 - Prob. 49ECh. 11.3 - Prob. 50ECh. 11.3 - Prob. 51ECh. 11.3 - The article Spray Flu Vaccine May Work Better Than...Ch. 11.3 - Prob. 53ECh. 11.3 - The following quote is from the article Canadians...Ch. 11.3 - Prob. 55ECh. 11.3 - Women diagnosed with breast cancer whose tumors...Ch. 11.3 - Prob. 57ECh. 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 - Prob. 61CRCh. 11 - Prob. 62CRCh. 11 - A deficiency of the trace element selenium in the...Ch. 11 - Prob. 64CRCh. 11 - Prob. 65CRCh. 11 - In a study of a proposed treatment for diabetes...Ch. 11 - When a surgeon repairs injuries, sutures (stitched...Ch. 11 - Prob. 68CRCh. 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 - Prob. 71CRCh. 11 - Prob. 72CRCh. 11 - The article Truth and DARE: Tracking Drug...Ch. 11 - The article Softball Sliding Injuries (American...Ch. 11 - Prob. 75CRCh. 11 - Wayne Gretzky was one of ice hockeys most prolific...Ch. 11 - Heres one to sink your teeth into: The authors of...Ch. 11 - Prob. 78CRCh. 11 - Dentists make many people nervous. To see whether...Ch. 11 - Prob. 80CRCh. 11 - Prob. 81CRCh. 11 - Both surface soil and subsoil specimens were taken...
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