Weighted Mean - HP -22S Owner's Manual

Weighted Mean
The following procedure calculates the weighted mean of data points
xl'
X2' .. . Xn
occurring with weights
YI' Y2' .. . Yn.
The weights can be
integer or non-integer values.
1. Use
I 2:+ 1
to enter the data as x,y-pairs. The y-values are the
weights of the x-values.
2. Press
I STAT 1 {i,y} {iw}.
Example: Weighted Mean. Your manufacturing company purchases
a certain part four times a year. Last year's purchases were:
Price per part
$4.25 $4.60 $4.70 $4.10
Number of Parts
250 800 900 1000
Calculate the weighted mean of the price data.
Keys:
4.25
'INPUT
1 250
'2:+
1
4.6
I
INPUT
1
800 ,
2:+
1
4.7
'INPUT I
900
'2:+ 1
4.1
'INPUT
11000
'2:+
1
I STAT 1 {i,y} {iw}
Display:
n=4.0000
iw=4.4314
68 Statistical Calculations
Description:
Clears the statistical
registers.
Enters the data and
their weights.
Calculates weighted
mean.