This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Chapter 7 Inference for Distributions Chapter 7 1 Introduction Our study of Exploratory Data Analysis proceeded in two steps: Graphical techniques and numerical summaries for the distribution of a single variable (Chapter 1) Graphical techniques and numerical summaries for the relationship between two variables (Chapter 2) Our study of Statistical Inference will proceed in a similar fashion. Inference for parameters of a single distribution. Inference for parameters describing the relationship between two variables. Inference for the comparison of parameters for two or more distributions. Chapter 7 2 Inference in Practice In Chapter 6, we introduced confidence intervals and tests of significance. Our procedures used the onesample zstatistic. We made the somewhat unrealistic assumption that was known. Chapter 7 emphasizes some of the most common tools for statistical inference. Chapter 7 3 Section 7.1 Inference for the Mean of a Population Section 7.1 4 Introduction Confidence intervals for the population mean are centered on the sample mean x . Test statistics for significance tests also use x . The sampling distribution of x is known when the population standard deviation is known. In practice, we must also estimate , even though we are primarily interested in . We can estimate using the sample standard deviation s . Section 7.1 5 Sampling Distribution of x Suppose we have a simple random sample (SRS) from a population that has a Normal distribution with mean and standard deviation . The sample mean x has distribution N , n Section 7.1 6 Estimating When is unknown, we estimate it with the sample standard deviation s ....
View Full
Document
 Spring '08
 ABBEY

Click to edit the document details