R/statpsych3.R
size.ci.prop.Rd
Computes the sample size required to estimate a population proportion with desired confidence interval precision. Set the proportion planning value to .5 for a conservatively large sample size.
size.ci.prop(alpha, p, w)
alpha level for 1-alpha confidence
planning value of proportion
desired confidence interval width
Returns the required sample size
size.ci.prop(.05, .4, .2) #> Sample size #> 93 # Should return: # Sample size # 93