×

### Let's log you in.

or

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

×

or

by: Debra Tee

3

0

3

# Lecture 9 STATS 250

Debra Tee
UM
GPA 3.85

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

×
Unlock Preview

Overview of Confidence Intervals and Confidence Interval for a Population Proportion
COURSE
PROF.
Thomas Venable Jr
TYPE
Class Notes
PAGES
3
WORDS
CONCEPTS
confidence, interval, population, proportion
KARMA
25 ?

## Popular in Statistics

This 3 page Class Notes was uploaded by Debra Tee on Thursday October 13, 2016. The Class Notes belongs to STATS 250 at University of Michigan taught by Thomas Venable Jr in Fall. Since its upload, it has received 3 views. For similar materials see /class/231658/stats-250-university-of-michigan in Statistics at University of Michigan.

×

## Reviews for Lecture 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: 10/13/16
Lecture  9:  Estimating  Proportions  with  Confidence     10.1:  Overview  of  Confidence  Intervals       Confidence  Intervals  concept:  Use  sample  data  to  estimate  a  population   parameter     Population  (size  N)  =  the  whole  group  that  we  want  to  make  conclusions  on   Parameter  =  summary  about  population     Random  sample  of  size  n  =  a  few  units  selected  from  population   Statistic  =  summary  about  the  sample   Sample  estimate  =  provides  our  best  guess  as  to  what  is  the  value  of  the   population  parameter,  but  it  is  not  100%  accurate.     Concept:   The  value  of  the  sample  estimate  will  vary  from  one  sample  to   the  next.   The  values  often  vary  around  the  population  parameter  and  the  standard   deviation  give  an  idea  about  how  far  the  sample  estimates  tend  to  be  from   the  true  population  proportion  on  average.       The  standard  error  of  the  sample  estimate  provides  an  idea  of  how  far   away  it  would  tend  to  vary  from  the  parameter  value  (on  average).     The  general  format  for  a  confidence  interval  estimate  is  given  by:   Sample  estimate  ±  (a  few)  standard  errors             10.2:  Confidence  Interval  for  a  Population  Proportion  p         Probability  that  sample  proportion  ????  will  be  within  2  standard  deviations   from  the  true  proportion  p  =  95%.           Common  mistake:     Can  we  say  that  95%  of  the  time  the  population  prop ortion  p  will  be  in  the   confidence  interval  for  ?????  NO,  either  p  is  in  the  particular  interval  or  it  is  not!     Interpreting  the  Confidence  Level:   Definition  of  95%  Confidence  Level:  If  the  sampling  procedure  were   repeated  many  times,  then  approximately  95%  of  the  resulting  confidence   intervals  would  contain  the  population  proportion  of  xxx…     Important  concept:  When  Confidence  level  increases,  width  of  confidence   interval  increases.     Example:  90%  Confidence  Interval  would  be  narrower  than  95%   Confidence  Interval.

×

×

### 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

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!"

Kyle Maynard Purdue

#### "When you're taking detailed notes and trying to help everyone else out in the class, it really helps you learn and understand the material...plus I made \$280 on my first study guide!"

Bentley McCaw University of Florida

Forbes

#### "Their 'Elite Notetakers' are making over \$1,200/month in sales by creating high quality content that helps their classmates in a time of need."

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