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Just a note

But take care to note whether it is giving the proportion (P) of the distribution that is less than the Z-value you give it, or 1-P which is the proportion of the distribution greater than the Z-value you give it, in other words the proportion in this distribution's upper-tail.
    To save space, published statistical tables only give upper-tail quantiles for 1-P.

For example R's pnorm function gives the proportion less than (the standard normal quantile) Z - and this is true of its cumulative probability functions for every other distribution.

Whereas in Statistica, if you enter the Z-value as X with no boxes clicked, it gives the proportion that is less than Z. If you click (1-cumulative P), Statistica gives the proportion that is greater than Z.

BEWARE!!!

    Most stats textbook calculations, and many stats publications, assume you are using published statistical tables.