Sample Size Calculator For Comparing Two Groups
Sample Size Calculator For Comparing Two Groups: a planned Super Calculator tool. Stub page: the tool, its formula and a worked example are not published yet.
Sample Size Calculator For Comparing Two Groups is a planned calculator in the mathematics section of Super Calculator, covering statistics and probability.
What this calculator will compute
Inputs: outcome type (mean or proportion), expected effect, alpha, target power (%), allocation ratio and dropout rate (%).
Outputs: n per group, total n, n inflated for dropout and achieved power.
Formula, recorded as scope and not yet verified against a primary source: n per group = 2 * ((z_(1-alpha/2) + z_(1-beta)) / d)^2 for means with standardized effect d, or n = (z_(1-alpha/2)sqrt(2pbar*(1-pbar)) + z_(1-beta)*sqrt(p1(1-p1)+p2(1-p2)))^2 / (p1-p2)^2 for proportions. Unequal allocation ratio k adjusts both arms.
Status
This page is a stub. The calculator is not built, no figure on this page has been verified against the authority that sets it, and nothing here should be used to make a decision. The page exists so that the site structure is complete and so that articles can link this concept on first mention.
The stub carries noindex, nofollow and is excluded from the sitemap.