Mean - HP -11C Owner's Handbook Manual

60
Mean
Section 3: Numeric Functions
The function computes the artithmetic mean (average) of the x
and y statistics accumulated in registers R; and R, respectively.
When you press [9][3]):
The contents of the stack registers lift in the same way as
when you press [RCL][ 2 + ] , as described on page 57.
The mean of the x values (x) is calculated using the statistics
accumulated in R;(2x) and Ry(n). The mean of the y values
(¥) is calculated using the data accumulated in registers
R3(Zy) and Ry(n). The formulas used are shown below.
X - Sy
y=—
n n
x =
The values for X and y are placed in the X- and Y-registers of
the stack.
T+
S
&= ya
X=>
Example. From the five year statistical data you accumulated
(and corrected) in the previous example, calculate the average coal
production and electrical output for the entire period.
Keystrokes Display
6.1352 Average electrical output
(average of X-register
inputs) for the five-year
period.
xZy 1.8316 Average coal production
(average Y-register
inputs) for the five-year
period.