Lower and upper bounds of a two-sided confidence interval.
Arguments
x
number of 'successes'
n
number of trials
conf.level
confidence level
Author
Randall Pruim
Details
wald.ci produces Wald confidence intervals. wilson.ci
produces Wilson confidence intervals (also called ``plus-4'' confidence
intervals) which are Wald intervals computed from data formed by adding 2
successes and 2 failures. The Wilson confidence intervals have better
coverage rates for small samples.
References
A. Agresti and B. A. Coull, Approximate is better then `exact'
for interval estimation of binomial proportions, American
Statistician 52 (1998), 119--126.