Calculate P values from the t distribution, corresponding to specified t statistic and degrees of freedom. Also calculates critical values for the same t distribution corresponding to the specified alpha (significance) level.

Inputs are the t statistic, degrees of freedom for the distribution and the specified alpha for calculation of critical values.

The program outputs 1- and 2-tailed P values, 1- and 2-tailed critical values and the probabilities associated with values greater than or less than the observed t value, as well as a summary and plot of the distribution.