Statistics and Probability Dictionary
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The t statistic (aka, the t score) is defined
t = [ x - μ ]
/ [ s / sqrt( n ) ]
where x is the sample mean, μ
is the population mean, s is the standard deviation of the sample, and n is the
The distribution of this t statistic is called the t distribution
or the Student t distribution. The
can be used whenever samples are drawn from populations
possessing a bell-shaped distribution (i.e., approximately normal).