The t-distribution allows the calculation of confidence intervals for means when the actual standard error is not known.

T-Distribution

A type of probability distribution that arises when estimating the mean of a normally distributed population in situations where the sample size is small and population standard deviation is unknown.

Confidence Intervals

Statistical intervals that estimate where a population parameter, based on sample data, is expected to lie, including a range of possible values.

Standard Error

A measure of the precision or variability of a sample statistic estimate of a population parameter.