Chapter 10: Confidence Intervals

1 / 6

# Chapter 10: Confidence Intervals - PowerPoint PPT Presentation

Chapter 10: Confidence Intervals. Section 2: Estimating a Population Proportion. Margin of Error. To calculate our margin of error in this case, we will use:. CI for Population Proportion (when p is known ).

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'Chapter 10: Confidence Intervals' - tea

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Chapter 10: Confidence Intervals

Section 2: Estimating a Population Proportion

Margin of Error
• To calculate our margin of error in this case, we will use:
CI for Population Proportion(when pis known)
• Choose a SRS of size n from a population having unknown proportion p of successes. An approximate level C confidence interval for pis:
PRACTICE IT!
• A May 2000 Gallup Poll found that 38% of a random sample of 1012 adults said that they believe in ghosts. Find a 95% confidence interval for the true proportion of adults who believe in ghost.
• We are 95% confident that the true proportion of adults who believe in ghosts is between 35% and 41%.
Determining Sample Size
• If we wanted to determine an appropriate sample size for a desired margin of error we would use:
PRACTICE IT!
• Another Gallop Poll is taken in order to measure the proportion of adults who approve of attempts to clone humans. What sample size is necessary to be within + 0.04 of the true proportion of adults who approve of attempts to clone humans with a 95% Confidence Interval?