SAMPSIZE_p_sp08

SAMPSIZE_p_sp08 - 5.3 Determining Sample Size to Estimate p...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
5.3 Determining Sample Size to Estimate p
Background image of page 1

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

View Full DocumentRight Arrow Icon
To Estimate a Population Proportion p If you desire a C% confidence interval for a population proportion p with an accuracy specified by you, how large does the sample size need to be? We will denote the accuracy by SE, which stands for S ampling E rror.
Background image of page 2
Required Sample Size n to Estimate a Population Proportion p * * * ˆ ± = 2 2 pq CIforp: p z n pq set z SE and solve for n: n z pq n = ; (SE)
Background image of page 3

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

View Full DocumentRight Arrow Icon
Background image of page 4
What About p and q= 1- p ? * 2 2 z pq n = ; we don't know p or q; (SE) TWO METHODS: 1: if prior information is available concerning the value of p, use that estimate to calculate n; 2: if no prior information about p is available, to obt = = ain a conservative estimate of the 1 required sample size, use p q 2
Background image of page 5

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

View Full DocumentRight Arrow Icon
Example: Sample Size to Estimate a Population Proportion p The U. S. Crime Commission wants to estimate p = the proportion of crimes in which firearms are used to within .02 with 90% confidence. Data from previous years shows that p is about .6
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/21/2009 for the course BUS 350 taught by Professor Reiland during the Spring '08 term at N.C. State.

Page1 / 10

SAMPSIZE_p_sp08 - 5.3 Determining Sample Size to Estimate p...

This preview shows document pages 1 - 7. Sign up to view the full document.

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