Sample Size Determination
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Two Samples Proportions: Estimation of difference
This utility can be used to calculate required sample size when your aim is to estimate difference between two sample proportions with specified proportions.
Formula used and other details
Your guesstimate of first Sample Proportion (P1)
Enter positive number between 0.01 to 99.99
Required
In Percentage. Approxiate estimate of first Sample proportion based on previous studies / pilot studies etc. Should be between 0.01 and 99.99.
Your guesstimate of second Sample proportion (P2)
Enter positive number between 0.01 to 99.99
Required
In Percentage. Approxiate estimate of second Sample proportion based on previous studies / pilot studies etc. Should be between 0.01 and 99.99.
Ratio of Sample Size in two Groups (N2 / N1)
Enter number from 0.01 to 9.00
Required
Sample Size in Group 2 / Saple Size in Group 1
Confidence Level %
Enter positive number between 0.01 to 99.99
Required
In percentage. Commonly used values are 95, 99 and 90. Should be between 0.01 to 99.99.
Precision (allowable error)
This is the absolute error towards both sides of true difference between proportions you can allow.
Sample Size Required =