This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: lecture 19, Statistical Inference Based on Two Samples 1 / 31 Comparing Two Population Means by Using Independent Samples: Variances Known zBased Confidence Interval for the Difference in Means (Variances Known) zBased Test About the Difference in Means (Variances Known) Comparing Two Population Means by Using Large, Independent Samples: Variances lecture 19, Statistical Inference Based on Two Samples Outline 1 Comparing Two Population Means by Using Independent Samples: Variances Known zBased Confidence Interval for the Difference in Means (Variances Known) zBased Test About the Difference in Means (Variances Known) 2 Comparing Two Population Means by Using Large, Independent Samples: Variances Unknown zBased Confidence Interval for the Difference in Means (Large Samples, Variances Unknown) zBased Test About the Difference in Means (Large Samples, Variances Unknown) 3 Comparing Two Population Proportions by Using Large, Independent Samples lecture 19, Statistical Inference Based on Two Samples 2 / 31 Comparing Two Population Means by Using Independent Samples: Variances Known zBased Confidence Interval for the Difference in Means (Variances Known) zBased Test About the Difference in Means (Variances Known) Comparing Two Population Means by Using Large, Independent Samples: Variances lecture 19, Statistical Inference Based on Two Samples Comparing Two Population Means by Using Independent Samples: Variances Known Motivations • Business improvement often requires making comparisons • Examples: • Compare different types of advertising campaigns • Compare the profitability of different investment portfolios • Compare different production methods • In this lecture, we discuss how to use confidence intervals and hypothesis testing to compare two populations • We compare two population means/population proportions by studying their differences. lecture 19, Statistical Inference Based on Two Samples 3 / 31 Comparing Two Population Means by Using Independent Samples: Variances Known zBased Confidence Interval for the Difference in Means (Variances Known) zBased Test About the Difference in Means (Variances Known) Comparing Two Population Means by Using Large, Independent Samples: Variances lecture 19, Statistical Inference Based on Two Samples Comparing Two Population Means by Using Independent Samples: Variances Known Sampling Distribution of the Difference of Two Sample Means • Suppose Population 1 has mean μ 1 and variance σ 2 1 • Take a random sample of size n 1 from population 1, and denote its (sample) mean and variance by ¯ X 1 and variance S 2 1 . • Suppose Population 2 has mean μ 2 and variance σ 2 2 • Take a random sample of size n 2 from population 2, and denote its (sample) mean and variance by ¯ X 2 and variance S 2 2 ....
View
Full Document
 Fall '10
 YingYingLi
 Business, Normal Distribution, variances, independent samples, independent sample, Statistical Inference Based

Click to edit the document details