day17 - The Population Proportion The population proportion...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
The Population Proportion The population proportion is p (generally unknown). The sample proportion is ¯ p . We use the sample proportion ¯ p to estimate the population proportion p . Example : In a survey of 1500 American adults released on October 13, 2010, 46% of those questioned said they approved of the job Barack Obama is doing as president. We would also like to make confidence intervals for the population propor- tion. In order to do this, we need to know the sampling distribution of the sample proportion ¯ p . The expected value of the sampling distribution of ¯ p is: The standard error of the sampling distribution of ¯ p is σ ¯ p : The sampling distribution of ¯ p will be approximately normal if np 5 and n (1 - p ) 5 . 1
Background image of page 1

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

View Full DocumentRight Arrow Icon
Example : A simple random sample of size 100 is selected from a population with p = 0 . 40. a. What is the expected value of ¯ p ? b. What is the standard error of ¯
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/24/2011 for the course STATISTICS 19897 taught by Professor Jager,abigaill during the Fall '10 term at Kansas State University.

Page1 / 6

day17 - The Population Proportion The population proportion...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online