SamplesizeSamplingMethods

SamplesizeSamplingMethods - Example Want to determine...

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Estimating Sample Size For confidence interval for p For confidence interval for population mean Need to select confidence coefficient and the error level you desire
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Estimating Population p Use the formula for ME Error level = ME Need estimate of p to determine sample size n
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Estimate of p 1. Prior study estimate for p 2. Most conservative estimate will give the largest sample size needed ( set p est = .5) 3. Take a small sample of say 30-50 and estimate p; then use that estimate to find the needed sample size. Use what you already took as part of the final sample
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Unformatted text preview: Example Want to determine sample size needed for 95% CI on p with an error rate of 5%, 3%, and 1% (No prior estimate available) Sample Size to Estimate mu Use formula for ME, confidence level, and estimate of sigma If no estimate of sigma available, can specify as a fraction of the error Example How large sample is needed to estimate mu with a 95% confidence interval and let ME be 1/5 of sigma? Methods for Sampling 1. Simple random sample 2. Systematic sampling 3. Cluster sampling 4. Stratified sampling...
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This note was uploaded on 03/16/2009 for the course ECN 221 taught by Professor Roberts during the Spring '07 term at ASU.

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SamplesizeSamplingMethods - Example Want to determine...

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