Learning Materials
Features
Discover
Chapter 9: Q.17 (page 547)
Explain in plain language why a significance test that is significant at the 1% level must always be significant at the 5% level. If a test is significant at the 5% level, what can you say about its significance at the 1% level?
It is not known the significance atlevel.
Over 30 million students worldwide already upgrade their learning with 91影视!
All the tools & learning materials you need for study success - in one app.
Get started for free
Improving health A large company's medical director launches a health promotion campaign to encourage employees to exercise more and eat better foods. One measure of the effectiveness of such a program is a drop in blood pressure. The director chooses a random sample of employees and compares their blood pressures from physical cams given before the campaign and again a year later. The mean change (after - before) in systolic blood pressure for these employees is and the standard deviation is .
(a) Do these data provide convincing evidence of an average decrease in blood pressure among all of the company's employees during this year? Carry out a test at the significance level.
(b) Can we conclude that the health campaign caused a decrease in blood pressure? Why or why not?
Describe a Type I error in this setting.
A change is made that should improve student satisfaction with the parking situation at your school. Right now, 37% of students approve of the parking that鈥檚 provided. The null hypothesis is tested against the alternative.
Anemia For the study of Jordanian children in Exercise , the sample mean hemoglobin level was mg/dl and the sample standard deviation was mg/dl.
(a) Calculate the test statistic.
(b) Find the P-value using Table . Then obtain a
more precise P-value from your calculator.
Flu vaccine A drug company has developed a new vaccine for preventing the flu. The company claims that fewer than of adults who use its vaccine will get the flu. To test the claim, researchers give the vaccine to a random sample of adults. Of these, get the flu.
(a) Do these data provide convincing evidence to support the company's claim? Perform an appropriate test to support your answer.
(b) Which kind of mistake - a Type I error or a Type II error-could you have made in (a)? Explain.
(c) From the company's point of view, would a Type I error or Type Il error be more serious? Why?
What do you think about this solution?
We value your feedback to improve our textbook solutions.
Explanations 
Textbooks 
Flashcards 
91影视 AI 
Notes 
Study Plans 
Study Sets 
Find a degree 
Magazine