# nProp: Compute simple random sample size for estimating a proportion In PracTools: Tools for Designing and Weighting Survey Samples

## Description

Compute the simple random sample size for estimating a proportion based on different precision requirements.

## Usage

 `1` ```nProp(CV0 = NULL, V0 = NULL, pU = NULL, N = Inf) ```

## Arguments

 `CV0` target value of coefficient of variation of the estimated proportion `V0` target value of variance of the estimated proportion `pU` population proportion `N` number of units in finite population

## Details

The precision requirement of p_s can be set based on either a target coefficient of variation, CV_0, or a target variance, V_0. In either case, a value of p_U must be supplied.

## Value

numeric sample size

## Author(s)

Richard Valliant, Jill A. Dever, Frauke Kreuter

## References

Valliant, R., Dever, J., Kreuter, F. (2013, chap. 3). Practical Tools for Designing and Weighting Survey Samples. New York: Springer.

`nCont`, `nLogOdds`, `nPropMoe`, `nWilson`

## Examples

 ```1 2 3 4 5 6 7 8``` ```# srs sample size so that CV of estimated proportion is 0.05 # assuming the population is large and pU=0.01 # Both examples below are equivalent nProp(V0=0.0005^2, N=Inf, pU=0.01) #or nProp(CV0=0.05, N=Inf, pU=0.01) # srswor sample size so that half-width of 2-sided 95% CI is 0.005 nProp(V0=(0.005/1.96)^2, N=Inf, pU=0.01) ```

### Example output

```[1] 39600
[1] 39600
[1] 1521.274
```

PracTools documentation built on June 13, 2018, 9:03 a.m.