Handout2 - STAT 454/854 Winter 2009 Handout #2 Sample Size...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: STAT 454/854 Winter 2009 Handout #2 Sample Size Calculation Under SRSWOR (1) Precision specified by P ( | ¯ y- μ y | < e ) = 1- α n . = z 2 α/ 2 σ 2 y e 2 + z 2 α/ 2 σ 2 y /N (2) Precision specified by P ( | ¯ y- μ y | /μ y < e ) = 1- α n . = z 2 α/ 2 σ 2 y e 2 μ 2 y + z 2 α/ 2 σ 2 y /N (3) Sample size calculation for estimating population proportion p = M/N This is a special case of (1) or (2) above, with μ y = p and σ 2 y . = p (1- p ). Sample Size Allocation Under Stratified SRSWOR (0) Variance formula under an arbitrary allocation V (¯ y st ) = H X h =1 W 2 h 1- n h N h σ 2 yh n h . (1) Proportional allocation The overall sample size n is fixed; n h = n ( N h /N ) = nW h , h = 1 , 2 , ··· ,H . Variance formula in this case can be written as V prop (¯ y ) = 1- n N 1 n H X h =1 W h σ 2 yh . When ( N h- 1) / ( N- 1) . = N h / ( N- 1) . = W h , we have V (¯ y )- V prop (¯ y st ) ....
View Full Document

This note was uploaded on 11/23/2010 for the course STAT 454 taught by Professor Da during the Fall '09 term at Waterloo.

Page1 / 2

Handout2 - STAT 454/854 Winter 2009 Handout #2 Sample Size...

This preview shows document pages 1 - 2. Sign up to view the full document.

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