Function Confidence-Interval-Z-Summaries
(
confidence-interval-z-summaries < mean > < standard-error > < confidence > )
This function is just like `confidence-interval-z,' except that instead of
its arguments being the actual data, it takes the following summary statistics:
`mean', a point estimator of the mean of some normally distributed population;
and the `standard-error' of the estimator, that is, the estimated standard
deviation of the normal population. `Confidence' should be a number between 0
and 1, exclusive.