Chapter 8: Problem 62
When comparing two sample proportions with a two-sided alternative hypothesis, all other factors being equal, will you get a smaller p-value with a larger sample size or a smaller sample size? Explain.
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 8: Problem 62
When comparing two sample proportions with a two-sided alternative hypothesis, all other factors being equal, will you get a smaller p-value with a larger sample size or a smaller sample size? Explain.
All the tools & learning materials you need for study success - in one app.
Get started for free
By establishing a small value for the significance level, are we guarding against the first type of error (rejecting the null hypothesis when it is true) or guarding against the second type of error?
Give the null and alternative hypothesis for each test, and state whether a oneproportion z-test or a two-proportion z-test would be appropriate. a. You test a random sample of eighth-grade students who play daily for 3 hours and devote the same time to homework, comparing boys and girls. b. You test a person to see whether she can tell butter on bread from margarine spread on bread. You give her 20 toast bits selected randomly (half with butter and half with margarine) and record the proportion she gets correct to test the hypothesis.
In the mid-1800s, Dr. Ignaz Semmelweiss decided to make doctors wash their hands with a strong disinfectant between patients at a clinic with a death rate of \(9.9 \%\). Semmelweiss wanted to test the hypothesis that the death rate would go down after the new hand-washing procedure was used. What null and alternative hypotheses should he have used? Explain, using both words and symbols. Explain the meaning of any symbols you use.
Suppose you wanted to test the claim that more than half of French citizens support revising the tax regime and structure. Give the null and alternative hypotheses, and explain, using both words and symbols.
Historically (from about 2001 to 2005 ), about \(58 \%\) of Americans believed that Earth's temperature was rising ("global warming"). A March 2010 Gallup Poll sought to determine whether this proportion had changed. The poll interviewed 1014 adult Americans, and 527 said they believed that global warming was real. (Assume these 1014 adults represented a simple random sample.) a. What percentage in the sample believed global warming was real in 2010 ? Is this more or less than the historical \(58 \%\) ? b. Test the hypothesis that the proportion of Americans who believe global warming is real has changed. Use a significance level of \(0.05\). c. Choose the correct interpretation: j. In 2010 , the percentage of Americans who believe global warming is real is not significantly different from \(58 \%\). ii. In 2010 , the percentage of Americans who believe global warming is real has changed from the historical level of \(58 \%\).
What do you think about this solution?
We value your feedback to improve our textbook solutions.