- (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