size.ci.prop {statpsych} | R Documentation |
Sample size for a proportion confidence interval
Description
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.
Usage
size.ci.prop(alpha, p, w)
Arguments
alpha |
alpha level for 1-alpha confidence |
p |
planning value of proportion |
w |
desired confidence interval width |
Value
Returns the required sample size
Examples
size.ci.prop(.05, .4, .2)
# Should return:
# Sample size
# 93
[Package statpsych version 1.6.0 Index]