Confidence interval for mean (known sigma)

Source: R/ci_z.R

Calculates the confidence interval for the mean with known standard deviation, using the Z-statistic (normal distribution).

ci_z(x, sig, n, conf.level = 0.95, digits = 2)

Arguments

x

Sample mean
sig

Population standard deviation
n

Sample size
conf.level

Confidence level to use for the confidence interval (Default is 0.95)
digits

Number of digits to round to (Default is 2)

Value

A tibble with the mean, and lower and upper ends of the confidence interval

Examples

x <- 80
sig <- 15
n <- 20
ci_z(x, sig, n)

#> # A tibble: 1 × 3
#>    mean lower upper
#>   <dbl> <dbl> <dbl>
#> 1    80  73.4  86.6