# ci_mean: CI for the Population Mean In confintr: Confidence Intervals

 ci_mean R Documentation

## CI for the Population Mean

### Description

This function calculates CIs for the population mean. By default, Student's t method is used. Alternatively, Wald and bootstrap CIs are available.

### Usage

``````ci_mean(
x,
probs = c(0.025, 0.975),
type = c("t", "Wald", "bootstrap"),
boot_type = c("stud", "bca", "perc", "norm", "basic"),
R = 9999L,
seed = NULL,
...
)
``````

### Arguments

 `x` A numeric vector. `probs` Lower and upper probabilities, by default `c(0.025, 0.975)`. `type` Type of CI. One of "t" (default), "Wald", or "bootstrap". `boot_type` Type of bootstrap CI. Only used for `type = "bootstrap"`. `R` The number of bootstrap resamples. Only used for `type = "bootstrap"`. `seed` An integer random seed. Only used for `type = "bootstrap"`. `...` Further arguments passed to `boot::boot()`.

### Details

The default bootstrap type for the mean is "stud" (bootstrap t) as it enjoys the property of being second order accurate and has a stable variance estimator (see Efron, p. 188).

### Value

An object of class "cint" containing these components:

• `parameter`: Parameter specification.

• `interval`: CI for the parameter.

• `estimate`: Parameter estimate.

• `probs`: Lower and upper probabilities.

• `type`: Type of interval.

• `info`: Additional description.

### References

1. Smithson, M. (2003). Confidence intervals. Series: Quantitative Applications in the Social Sciences. New York, NY: Sage Publications.

2. Efron, B. and Tibshirani R. J. (1994). An Introduction to the Bootstrap. Chapman & Hall/CRC.

### Examples

``````x <- 1:100
ci_mean(x)
ci_mean(x, type = "bootstrap", R = 999, seed = 1)  # Use larger R
``````

confintr documentation built on June 7, 2023, 6:24 p.m.