size.ci.mean {statpsych} | R Documentation |
Sample size for a mean confidence interval
Description
Computes the sample size required to estimate a population mean with desired confidence interval precision. Set the variance planning value to the largest value within a plausible range for a conservatively large sample size.
Usage
size.ci.mean(alpha, var, w)
Arguments
alpha |
alpha level for 1-alpha confidence |
var |
planning value of response variable variance |
w |
desired confidence interval width |
Value
Returns the required sample size
Examples
size.ci.mean(.05, 264.4, 10)
# Should return:
# Sample size
# 43
[Package statpsych version 1.6.0 Index]