nsize {PASWR} | R Documentation |
Function to determine required sample size to be within a given margin of error
nsize(b, sigma = NULL, p = 0.5, conf.level = 0.95, type = "mu")
b |
the desired bound |
sigma |
population standard deviation; not required if using type
"pi" |
p |
estimate for the population proportion of successes; not required
if using type "mu" |
conf.level |
confidence level for the problem, restricted to lie between zero and one |
type |
character string, one of "mu" or "pi" , or
just the initial letter of each, indicating the appropriate parameter;
default value is "mu" |
Answer is based on a normal approximation when using type "pi".
Returns required sample size.
Alan T. Arnholt
nsize(b=0.015, p=0.5, conf.level=.95,type="pi") # Returns the required sample size (n) to estimate the population # proportion of successes with a 0.95 confidence interval # so that the margin of error is no more than 0.015 when the # estimate of the population propotion of successes is 0.5. # This is Example 8.25 part b. from PASWR. nsize(b=0.02, sigma=0.1,conf.level=.95,type="mu") # Returns the required sample size (n) to estimate the population # mean with a 0.95 confidence interval so that the margin # of error is no more than 0.02. This is Example 8.4 from PASWR.