HP 15c - Manual (Page 49)

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.