TAILIEUCHUNG - Ebook Introductory statistics (10th edition - Global edition): Part 2
(BQ) Part 2 book "Introductory statistics" hass contents: Confidence intervals for one population mean, inferences for two population means, inferences for population standard deviations, inferences for population proportions, Chi-Square procedures,.and other contents. | CHAPTER Confidence Intervals for One Population Mean 8 CHAPTER OBJECTIVES CHAPTER OUTLINE In this chapter, you begin your study of inferential statistics by examining methods for estimating the mean of a population. As you might suspect, the statistic used to estimate ¯ the population mean, μ, is the sample mean, x. Because of sampling error, you cannot ¯ expect x to equal μ exactly. Thus, providing information about the accuracy of the estimate is important, which leads to a discussion of confidence intervals, the main topic of this chapter. In Section , we provide the intuitive foundation for confidence intervals. Then, in Section , we present confidence intervals for one population mean when the population standard deviation, σ , is known. Although, in practice, σ is usually unknown, we first consider, for pedagogical reasons, the case where σ is known. In Section , we discuss confidence intervals for one population when the population standard deviation is unknown. As a prerequisite to that topic, we introduce and describe one of the most important distributions in inferential statistics—Student’s t. Estimating a Population Mean Confidence Intervals for One Population Mean When σ Is Known Confidence Intervals for One Population Mean When σ Is Unknown CASE STUDY Bank Robberies: A Statistical Analysis In the article “Robbing Banks” (Significance, Vol. 9, Issue 3, pp. 17−21) B. Reilly et al. studied several aspects of bank robberies. As these researchers state, “Robbing a bank is the staple crime of thrillers, movies and newspapers. But . . . bank robbery is not all it is cracked up to be.” The researchers concentrated on the factors that determine the amount of proceeds from bank robberies, and thus were able to work out both the economics of attempting one and of preventing one. In particular, the researchers revealed that the return on an average bank robbery per person per raid is modest indeed—so modest .
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