HP 39g Graphing Calculator - Manual (Page 134)

One-Proportion Z-Interval
Menu name Z^INT: 1 P
This option uses the Normal Z-distribution to calculate a
confidence interval for the proportion of successes in a
population for the case in which a sample of size, /?, has a
number of successes, x.
Inputs The inputs are:
Field name Definition
X
Sample success count.
n Sample size.
c Confidence level.
Results The results are:
Result Description
Critical Z Critical value for Z.
71 Min Lower bound for 7l.
71 Max Upper bound for n.
9-18 Inference aplet