HP 9g

E-23
,
Cpx or Cpy Potential capability precision of the x values or y values,
,
Cpkx or Cpky Minimum (CPU, CPL) of the x values or y values, where
CPU is the upper spec. limit of capability precision and
CPL is lower spec. limit of capability precision.
C
pkx
= Min (C
PUX
, C
PLX
) = C
px
(1–C
ax
)
C
pky
= Min (C
PUY
, C
PLY
) = C
py
(1–C
ay
)
ppm Parts per million, Defection Per Million Opportunities.
Note: When calculating process capability in 2-VAR mode, the x
n
and y
n
values are independent of each other.
Correcting Statistical Data
See Example 45.
1. Press [ DATA ].
2. To change the data, select DATA-INPUT. To change the upper or lower
spec. limit, select LIMIT. To change a
x
, select DISTR.
3. Press [ ] to scroll through the data until the entry you want to
change is displayed.
4. Enter the new data. The new data you enter overwrites the old entry.
5. Press [ ] or [ ] to save the change.
Note: The statistical data you enter is retained when you exit statistics mode.
To clear the data, select D-CL mode.
Probability Distribution (1-Var Data)
See Example 46.
1. Press [ DATA ] , select DISTR and press [ ].
2. Enter a a
x
value, then press [ ].
3. Press [ 2nd ] [ STATVAR ].
4. Press [ ] or [ ] to scroll through the statistical results until you find
the probability distribution variables you want (see table below).
Variable Meaning
t Test value
P(t) The cumulative fraction of the standard normal
distribution that is less than t.