ci.mean: Confidence interval for a mean

In statpsych: Statistical Methods for Psychologists

Confidence interval for a mean

Description

Computes a confidence interval for a population mean using the estimated mean, estimated standard deviation, and sample size. Use the t.test function for raw data input.

For more details, see Section 1.7 of Bonett (2021, Volume 1)

Usage

ci.mean(alpha, m, sd, n)

Arguments

alpha	alpha level for 1-alpha confidence
m	estimated mean
sd	estimated standard deviation
n	sample size

Value

Returns a 1-row matrix. The columns are:

• Estimate - estimated mean

• SE - standard error

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

References

\insertRef

Snedecor1980statpsych

\insertRef

Bonett2021statpsych

Examples

ci.mean(.05, 38.3, 8.14, 10)

# Should return:
# Estimate        SE       LL       UL
#     38.3  2.574094 32.47699 44.12301
 

statpsych documentation built on Jan. 13, 2026, 1:07 a.m.