Lecture20

# Lecture20 - STAT 350 Lecture 19 20 8.2 Tests Concerning...

This preview shows pages 1–8. Sign up to view the full content.

STAT 350 Lecture 19 & 20 8.2 Tests Concerning Hypotheses About Means

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Welcome Back Homework #9 due Friday: Ch8: 4,6,12,15,16,19,20,22,26,29 Please start homework today Wednesday: Lab 4: Testing Statistical Hypotheses Office Hours: Tuesday: 1:30 PM 2:30 PM Thursday: 10:30 AM 11:30 AM
8.2 Tests Concerning Hypotheses About Means Review: One-Sample z Test for population mean One-Sample z Test for population proportion One-sample t Test Two-sample t Test Tests with paired data

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
One-sample t Test for a single Mean: General Setting: X 1 , ., X n : SRS from (approximately) N(μ, σ ) μ is the unknown parameter of interest The null hypothesis is H 0 : μ = μ 0 The alternative hypothesis could be: H a : μ ≠ μ 0 (two-sided) H a : μ > μ 0 (one-sided) H a : μ < μ 0 (one-sided)
Setting up Hypotheses If an investigator wishes to demonstrate conclusively that a particular assertion is correct, or wants to see strong evidence for an assertion before taking action, that assertion should be incorporated in H a Please read page 346 in your textbook

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
One-sided vs. two-sided If, based on previous data or experience, we expect increase , more , better , etc. ( decrease , less , worse , resp.), then we can use a one sided test. Otherwise, by default, we use two-sided. Key words: different , departures , changed ”…
Test Statistic For population mean when the data is N(μ, σ ): Notes: df = n 1 Measures compatibility between null hypothesis and data If n is large (≥30), CLT guarantees a approximate normal distribution and the t can be replaced with z , where z follows a standard normal distribution.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern