×

### Let's log you in.

or

Don't have a StudySoup account? Create one here!

×

or

by: Qihua Wu

21

0

2

# Weekly Notes Intro Stat Week 9 TMATH 110 C

Marketplace > University of Washington Tacoma > Math > TMATH 110 C > Weekly Notes Intro Stat Week 9
Qihua Wu
University of Washington Tacoma
Intro Stat Applications
KENNEDY,MAUREEN C.

These notes were just uploaded, and will be ready to view shortly.

Either way, we'll remind you when they're ready :)

Get a free preview of these Notes, just enter your email below.

×
Unlock Preview

This week I included t-distribution and pointed out the difference between t-distribution and standard normal distribution.
COURSE
Intro Stat Applications
PROF.
KENNEDY,MAUREEN C.
TYPE
Class Notes
PAGES
2
WORDS
KARMA
25 ?

## Popular in Math

This 2 page Class Notes was uploaded by Qihua Wu on Sunday November 29, 2015. The Class Notes belongs to TMATH 110 C at University of Washington Tacoma taught by KENNEDY,MAUREEN C. in Fall 2015. Since its upload, it has received 21 views. For similar materials see Intro Stat Applications in Math at University of Washington Tacoma.

×

## Reviews for Weekly Notes Intro Stat Week 9

×

×

### What is Karma?

#### You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 11/29/15
Recall that in standard normal distribution we assume that we know the variance of the population yet it is uncommon in real life where we would know the variance of the population but not the mean Therefore we assume the variance of the population by using the sample variance However this then introduces an additional source of variability the variance on top of the sampling error of the mean in this case we use the tdistribution Comparing to standard normal distribution tdistribution has higher tails at the end making the occurrence of extreme values more usual because to preserve the con dence level when we have an additional source of variability we need to get larger values on the tails The tstatistic is distributed as a t distribution with sample size 1 degrees of freedom where the degrees of freedom in calculating statistics means the number of freely varying observations The reason why the degrees of freedom is sample size1 is because as we calculate the mean one value becomes xed To calculate the tstatistics for the estimated population mean based on the sample of size n instead of using variance of the population like the standard normal distribution we use the variance of the sample and instead of using 2 values we use t M tn1sampe mean population mean sample standard deviation n5 Assumptions for the tdistribution The sample mean is normally distributed either the sample itself is normally distributed or the sample size is greater than 30 The data are sampled from random sampling Properties of the tdistribution Symmetric at 0 since mean is normally distributed Goes from negative in nity to positive in nity More extreme values are seen as usual longer tails than normal standard distribution Distribution based on sample size different sample size results in different degrees of freedom which looking at the ttable result in different values which then cause different shape As degrees of freedom goes to in nity the mean approaches 0 and the variance approaches 1 because of the central limit theorem though the t distribution is still a bit more likely to have longer tails than standard normal distribution As sample size increases the critical values get smaller for a given con dence level because of central limit theorem As con dence level increase the critical values get bigger for a given sample size

×

×

### BOOM! Enjoy Your Free Notes!

×

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

## Why people love StudySoup

Jim McGreen Ohio University

#### "Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Allison Fischer University of Alabama

#### "I signed up to be an Elite Notetaker with 2 of my sorority sisters this semester. We just posted our notes weekly and were each making over \$600 per month. I LOVE StudySoup!"

Bentley McCaw University of Florida

#### "I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Parker Thompson 500 Startups

#### "It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!
×

### Refund Policy

#### STUDYSOUP CANCELLATION POLICY

All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email support@studysoup.com

#### STUDYSOUP REFUND POLICY

StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here: support@studysoup.com

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to support@studysoup.com