This preview shows pages 1–9. Sign up to view the full content.
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 DocumentThis 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: Statistics for Economists Lecture 14 Kata Bognar UCLA tInterval Procedures Hypothesis Testing Statistics for Economists Lecture 14 Kata Bognar UCLA May 20, 2010 Statistics for Economists Lecture 14 Kata Bognar UCLA tInterval Procedures Hypothesis Testing Announcements Midterm solutions are online Homework 5 solutions will be uploaded later this afternoon Statistics for Economists Lecture 14 Kata Bognar UCLA tInterval Procedures Hypothesis Testing Last Lectures Sampling distributions Point and interval estimators Statistics for Economists Lecture 14 Kata Bognar UCLA tInterval Procedures Hypothesis Testing Todays Outline 1 tInterval procedure 2 Hypothesis testing 3 Readings: Weiss, Chapter 8.4, 9.1  9.2 4 Readings for next class: Weiss, Chapter 9.3  9.6 Statistics for Economists Lecture 14 Kata Bognar UCLA tInterval Procedures Hypothesis Testing Known Population Standard Deviation The sampling distribution of the sample mean is the basis for finding confidence intervals for the population mean. The sampling distribution of the sample mean, X is normal with x = and x = n whenever the population is normal. approximately normal with x = and x = n whenever the sample is large ( n > 30). Thus, when the population is known, the distribution of the random variable Z = X / n is standard normal whenever the population is normal. approximately standard normal whenever the sample is large ( n > 30). Statistics for Economists Lecture 14 Kata Bognar UCLA tInterval Procedures Hypothesis Testing Unknown Population Standard Deviation What to do if we do not know the population standard deviation? We estimate the population standard deviation by the sample standard deviation, s . The random variable T = X s / n follows a Students tdistribution with a degree of freedom n 1. Statistics for Economists Lecture 14 Kata Bognar UCLA tInterval Procedures Hypothesis Testing tDistribution Statistics for Economists Lecture 14 Kata Bognar UCLA tInterval Procedures Hypothesis Testing Properties of the tDistribution The total area under a tcurve is 1....
View Full
Document
 Spring '07
 Guggenberger

Click to edit the document details