L21-ss

L21-ss - t-test Lecture 21 1 Last class t-distribution...

This preview shows pages 1–6. Sign up to view the full content.

t-test 6/9/11 Lecture 21 1

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

View Full Document
Last class: t-distribution: helps us do statistical inference when population SD is unknown Computed confidence intervals Today: Testing hypothesis using t-distribution 6/9/11 Lecture 21 2
For CI and hypothesis testing about a normal mean , when is unknown , the sample standard deviation s is used to estimate . Note: replaced by When is the mean of a random sample of size n from a normal distribution with mean , then has a t distribution with n - 1 degrees of freedom (df). X n s X t / n X z / t 6/9/11 Lecture 21 3

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

View Full Document
To determine number of workers required to meet demand, the productivity of new trainees is studied. It is believed trainees can process more than 450 packages per hour within one week of hiring. A sample of productivity of 50 trainees is observed and summarized as: Can we conclude that this belief is correct based on the sample? . 83 . 38 , 38 . 460 s x 6/9/11 Lecture 21 4
Null hypothesis: H 0 : = 0 Test statistic: H a p-value 0 2P ( T |t| ) > 0 P ( T t ) < 0 P ( T t ) .

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