Handout2

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

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

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

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