Introductory Statistics (2nd Edition)
2nd Edition
ISBN: 9780321978271
Author: Robert Gould, Colleen N. Ryan
Publisher: PEARSON
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Chapter 1, Problem 60CRE
HIV-1 and HIV-2 Does infection with HIV-2 slow the progression to AIDS for those with HIV-1? A blood test is used to determine whether a person is infected with HIV. If a person has AIDS, it means the person is experiencing symptoms that result from the HIV infection. (It is possible to be infected with HIV and not show symptoms.) Read the extract given, and then answer the questions that follow it.
Methods We analyzed data from 223 participants who were infected with HIV-1 after enrollment (with either HIV-1 infection alone or HIV-1 and HIV-2 infection) in a cohort with a long follow-up duration (approximately 20 years), according to whether HIV-2 infection occurred first and the time to the development of AIDS (time to AIDS) ….
Result The
a. Identify the treatment variable and the response variable.
b. Was this a controlled experiment or an observational study? Explain.
c. What do the median times to AIDS show, descriptively?
d. Can you conclude that the presence of HIV-2 slows the progression of HIV to AIDS? Why not?
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9.2 Testing the Mean mu:
Problem 3
(1 point)
Test the claim that the population of sophomore college
students has a mean grade point average greater than 2.2.
Sample statistics include n = 71, x = 2.44, and s = 0.9.
Use a significance level of a = 0.01.
The test statistic is
The P-Value is between :
The final conclusion is
< P-value <
A. There is sufficient evidence to support the claim that
the mean grade point average is greater than 2.2.
○ B. There is not sufficient evidence to support the claim
that the mean grade point average is greater than 2.2.
Note: You can earn partial credit on this problem.
Note: You are in the Reduced Scoring Period. All work counts for
50% of the original.
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Chapter 1 Solutions
Introductory Statistics (2nd Edition)
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