size.ci.ratio.prop2 {statpsych} | R Documentation |
Sample size for a 2-group proportion ratio confidence interval
Description
Computes the sample size in each group (assuming equal sample sizes) required to estimate a ratio of population proportions with desired confidence interval precision in a 2-group design.
Usage
size.ci.ratio.prop2(alpha, p1, p2, r)
Arguments
alpha |
alpha level for 1-alpha confidence |
p1 |
planning value of proportion for group 1 |
p2 |
planning value of proportion for group 2 |
r |
desired upper to lower confidence interval endpoint ratio |
Value
Returns the required sample size for each group
Examples
size.ci.ratio.prop2(.05, .2, .1, 2)
# Should return:
# Sample size per group
# 416
[Package statpsych version 1.6.0 Index]