CochranMOD: Modified Cochran's Formula

In Dcroix/RSamplingz: Package for Sampling Needs

Modified Cochran's Formula

Description

Computes a sample size for small populations

Usage

CochranMod(no,N)

Arguments

no	Computed value using the Cochran Formula
N	Population of the study

Details

Computes an adjusted sample size derived from Cochran's sample size recommendation for small populations

Value

Returns a vector which is the adjusted sample for the given population rounded up with ceiling function.

Note

Commonly used z-scores: r = 0.90; z-score = 1.645 | r = 0.95; z-score = 1.96 | r = 0.98; z-score = 2.326 | r = 0.99; z-score = 2.576 |

Author(s)

Paolo G. Hilado

References

Cochran, W.G. (1963). Sampling Techniques, 2nd Ed., New York: John Wiley and Sons, Inc.

Examples

CochranMod(289, 800)
[1] 213

## The function is currently defined as
CochranMod <- function(no, N){
  x <- no -1
  y <- x / N
  z <- 1 + y
  n <- no / z
  n <- ceiling(n)
  print(n)
}

Dcroix/RSamplingz documentation built on July 4, 2025, 12:23 p.m.