TAILIEUCHUNG - Ebook Elementary statistics - A step by step approach (8th edition): Part 2
(BQ) Part 2 book "Elementary statistics - A step by step approach" has contents: Hypothesis testing, testing the difference between two means, two proportions, and two variances; correlation and regression, other chi square tests, analysis of variance,. and other contents. | 9/9/10 11:48 AM Page 399 C H A P T E R 8 Hypothesis Testing Objectives After completing this chapter, you should be able to Outline Introduction 1 Understand the definitions used in hypothesis testing. 2 3 4 5 State the null and alternative hypotheses. 6 7 Test means when s is unknown, using the t test. Test proportions, using the z test. 8–5 X2 Test for a Variance or Standard Deviation 8 Test variances or standard deviations, using the chi-square test. 8–6 Additional Topics Regarding Hypothesis Testing 9 Test hypotheses, using confidence intervals. 8–1 Steps in Hypothesis Testing—Traditional Method Find critical values for the z test. 8–2 z Test for a Mean State the five steps used in hypothesis testing. 8–3 t Test for a Mean Test means when s is known, using the z test. 10 Explain the relationship between type I and 8–4 z Test for a Proportion Summary type II errors and the power of a test. 8–1 400 9/9/10 11:48 AM Page 400 Chapter 8 Hypothesis Testing Statistics Today How Much Better Is Better? Suppose a school superintendent reads an article which states that the overall mean score for the SAT is 910. Furthermore, suppose that, for a sample of students, the average of the SAT scores in the superintendent’s school district is 960. Can the superintendent conclude that the students in his school district scored higher on average? At first glance, you might be inclined to say yes, since 960 is higher than 910. But recall that the means of samples vary about the population mean when samples are selected from a specific population. So the question arises, Is there a real difference in the means, or is the difference simply due to chance (., sampling error)? In this chapter, you will learn how to answer that question by using statistics that explain hypothesis testing. See Statistics Today—Revisited for the answer. In this chapter, you will learn how to answer many questions of .
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