HP 50g Graphing Calculator - Manual (Page 275)

Page 8-18
3. Use function ΣLIST, once more, to calculate the denominator of s
w
:
4. Use the expression ANS(2)/ANS(1) to calculate the weighted average:
Thus, the weighted average of list S with weights in list W is s
w
= 2.2.
Statistics of grouped data
Grouped data is typically given by a table showing the frequency (w) of data in
data classes or bins. Each class or bin is represented by a class mark (s),
typically the midpoint of the class. An example of grouped data is shown next:
Note: ANS(1) refers to the most recent result (55), while ANS(2) refers to
the previous to last result (121).
Class Frequency
Class mark count
boundaries s
k
w
k
0 - 2 1 5
2 - 4 3 12
4 - 6 5 18
6 - 8 7 1
8 -10 9 3