Agresti-Coull add-4 CI for a binomial proportion

Description

Agresti-Coull add-4 CI for a binomial proportion, based on adding 2 successes and 2 failures before computing the Wald CI. The CI is truncated, when it overshoots the boundary

Usage

1
add4ci(x, n, conf.level)

Arguments

x

number of successes

n

number of trials

conf.level

confidence coefficient

Value

A list with class '"htest"' containing the following components:

conf.int

The confidence intervall for the proportion

estimate

The estimator for the proportion

References

Agresti, A., Coull, B. (1998) Approximate is better than exact for interval estimation of binomial proportions. The American Statistician 52, 119–126.

Agresti, A., Caffo, B.(2000) Simple and effective confidence intervals for proportions and difference of proportions result from adding two successes and two failures. The American Statistician 54 (4), 280–288.

Examples

1
add4ci(x = 15, n = 112, conf.level = 0.95)