Learning Materials
Features
Discover
Chapter 11: Q.5 (page 480)
What does the margin of error for the estimate of a population proportion tell you?
The margin of error is equal to half of the sureness (confidence) interval's length.
Over 30 million students worldwide already upgrade their learning with Vaia!
All the tools & learning materials you need for study success - in one app.
Get started for free
Folic Acid and Birth Defects. Refer to Exercise 11.107 and determine and interpret a confidence interval for the difference between the rates of major birth defects for babies born to women who have taken folic acid and those born to women who have not.
Racial Crossover. In the paper "The Racial Crossover in Comorbidity, Disability, and Mortality" (Demography, Vol. 37(3), pp. 267-283), N. Johnson investigated the health of independent random samples of white and African-American elderly (aged 70 years or older). Of the 4989 white elderly surveyed, 529 had at least one stroke, whereas 103 of the 906 African-American elderly surveyed - Lported at least one stroke. At the significance level, do the data suggest that there is a difference in stroke incidence between white and African-American elderly?
1Neutropenia. Neutropenia is an abnormally low number o neutrophils (a type of white blood cell) in the blood. Chemotherapy often reduces the number of neutrophils to a level that makes the patient susceptible to fever and infections. G. Bucaneve et al. published a study of such cancer patients in the paper "Levofloxacin to Prevent Bacterial Infection in Patients With Cancer and Neutropenia" (New England Journal of Medicine, Vol. 353, No, 10, pp. 977-987). For the study. 375 patients were randomly assigned to receive a daily dose of levofloxacin, and 363 were given a placebo. In the group receiving levofloxacin, fever was present in 243 patients for the duration of neutropenia, whereas fever was experienced by 308 patients in the placebo group.
a. At the1% significance level, do the data provide sufficient evidence to conclude that levofloxacin is effective in reducing the occurrence of fever in such patients?
b. Find a98% confidence level for the difference in the proportions of such cancer patients who would experience fever for the duration of neutropenia
Life Support. In , the Terri Schiavo case focused national attention on the issue of withdrawal of life support from terminally ill patients or those in a vegetative state. A Harris Poll of U.S. adults was conducted by telephone on April , Of those surveyed, had experienced the death of at least one family member or close friend within the last years who died after the removal of life support. Find and interpret a confidence interval for the proportion of all U.S. adults who had experienced the death of at least one family member or close friend within the last years after life support had been withdrawn.
Margin of error
Confidence level
Educated guess
(a) Obtain a sample size that will ensure a margin of error of at most the one specified (provided of course that the observed value of the sample proportion is further from that of the educated guess.
(b). Compare your answer to the corresponding one and explain the reason for the difference, if any.
What do you think about this solution?
We value your feedback to improve our textbook solutions.
Explanations 
Textbooks 
Exams 
GCSE 
IGCSE 
AS 
A Level 
International A Level 
University Admissions Tests 
Flashcards 
Vaia AI 
Notes 
Study Plans 
Study Sets 
Find a job 
Find a degree 
Student Deals 
Magazine 
Mobile App