HP HP-15C, Руководство пользователя

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Section 4: Statistics Functions 49
Keystrokes Display
l´
# 0.2809
Recall last random number generated,
which is the new seed. (The
´
may be
omitted.)
Accumulating Statistics
The HP-15C performs one- and two-variable statistical calculations. The
data is first entered into the Y- and X-registers. Then the
z
function
automatically calculates and stores statistics of the data in storage registers
R
2
through R
7
.
These registers are therefore referred to as the
statistics
registers .
Before beginning to accumulate statistics for a new set of data, press
´
CLEAR
∑
to clear the statistics registers and stack. (If you have
reallocated registers in memory and any of the statistics registers no longer
exist,
Error 3
will be displayed when you try to use
CLEAR
∑
,
z
, or
w
Appendix C explains how to reallocate memory.)
In one-variable statistical calculations, enter each data point ( x -value) by
keying in x and then press
z
.
In two-variable statistical calculations, enter each data pair (the x - and y -
values) as follows:
1. Key y into the display first.
2. Press
v
. The displayed y -value is copied into the Y-register.
3. Key x into the display.
4. Press
z
.
The current number of accumulated data points, n, will be
displayed. The x -value is saved in the LAST X register and y remains
in the Y-register.
z
disable stack lift, so the stack will not lift
when the next number is keyed in.