Cochran Formula For Known Population. Build your survey now. Mar 03 2020 Thus 186 sample size arrived at should be corrected adjusted for finite population.
Where n is the sample size N is the population size and e is the level of precision. L Ey E L WhYh w yh hl hl snce the estimates are unbiased in individual strata. This formula was used to calculate the sample sizes in Tables 2 and 3 and is shown below.
Displaystyle widehat sigma 2 frac 1 nsum left X_ i- overline Xright 2 Cochrans theorem shows that.
N an additional population quantity of interest is R PN i1 Yi PN i1 Xi Y X Y X the ratio of totals. Units are selected in a systematic way. σ 2 1 n X i X. William Cochran published his classic text Sampling Techniques in 1953.
