HP 39G

9-16 Inference aplet
Confidence intervals
The confidence interval calculations that the HP 39G/40G can
perform are based on the Normal Z–distribution or Student’s
t–distribution.
One–Sample Z–Interval
Menu name Z–INT: 1 µ
This option uses the Normal Z–distribution to calculate a
confidence interval for µ, the true mean of a population, when
the true population standard deviation, σ, is known.
Inputs The inputs are:
Results The results are:
Field name Definition
Sample mean.
σ Population standard deviation.
n Sample size.
C Confidence level.
x
Result Description
Critical Z Critical value for Z.
µ min Lower bound for µ.
µ max Upper bound for µ.