Sampling results 5 (10%) 74% 10 (20%) 25 (50%) 45 (90%) Sample Size

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Presentation transcript:

Sampling results 5 (10%) 74% 10 (20%) 25 (50%) 45 (90%) Sample Size Actual result (% green) Group 1 result (% green and difference) Group 2 result (% green and difference) Group 3 result (% green and difference) Group 4 result (% green and difference) 5 (10%) 74% 10 (20%) 25 (50%) 45 (90%)

Confidence intervals calculated via www.raosoft.com Population Sample size (n/%) Confidence in result 50 5 (10%) 95% +/- 42% 10 (20%) 95% +/- 28% 25 (50%) 95%+/- 14% 45 (90%) 95% +/- 5%

95% +/- 5% sample needed for different populations Sample size (95% +/-5%) Percentage sampled 50 45 90% 100 79 79% 200 132 66% 300 168 56% 400 196 49% 500 217 43.4% 1000 278 27.8% 10000 370 3.7%