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cicalc (version 0.1.0)

ci_prop_agresti_coull: Agresti-Coull CI

Description

Calculates the Agresti-Coull interval (created by Alan Agresti and Brent Coull) by (for 95% CI) adding two successes and two failures to the data and then using the Wald formula to construct a CI.

Usage

ci_prop_agresti_coull(x, conf.level = 0.95, data = NULL)

Value

An object containing the following components:

n

Number of responses

N

Total number

estimate

The point estimate of the proportion

conf.low

Lower bound of the confidence interval

conf.high

Upper bound of the confidence interval

conf.level

The confidence level used

method

Type of method used

Arguments

x

(binary/numeric/logical)
vector of a binary values, i.e. a logical vector, or numeric with values c(0, 1)

conf.level

(scalar numeric)
a scalar in (0,1) indicating the confidence level. Default is 0.95

data

(data.frame)
Optional data frame containing the variables specified in x and by.

Details

$$ \left( \frac{\tilde{p} + z^2_{\alpha/2}/2}{n + z^2_{\alpha/2}} \pm z_{\alpha/2} \sqrt{\frac{\tilde{p}(1 - \tilde{p})}{n} + \frac{z^2_{\alpha/2}}{4n^2}} \right)$$