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(t-significance t-value degrees-of-freedom #:tails)procedure

returns the probability of t-value for given degrees-of-freedom. The keyword #:tails modifies the calculation to be two-sided (the default) with ':both, or one-sided, ':positive or ':negative.

> (t-significance 0.2 5)
0.849360513995829
> (t-significance 0.2 5 #:tails ':positive)
0.424680256997915
> (t-significance 0.2 5 #:tails ':negative)
0.575319743002086