# T estimate of a mean

- Author:
- Hannu Mäkiö

- Topic:
- Confidence Interval

The mean of the sample depends on which values were selected.
The mean of the sample is a random variable.
When standard deviation of the population is unknown and we use standard deviation of the sample,
we need to use Student's t-distribution to calculate T estimate of a mean.
T estimate of a mean can also be calculated with probability calculator in Geogebra.