PropCIs (version 0.1-6)

add4ci: 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

add4ci(x, n, conf.level)

Arguments

x

number of successes

n

number of trials

conf.level

confidence coefficient

Value

• ll
  lower confidence bound
• ul
  upper confidence bound

References

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

Examples

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