HP 48gII - Manual (Page 270)

Page 8-15
and that we store it into a variable called S (The screen shot below shows this
action in ALG mode, however, the procedure in RPN mode is very similar.
Just keep in mind that in RPN mode you place the arguments of functions in
the stack before activating the function):
Harmonic mean of a list
This is a small enough sample that we can count on the screen the number of
elements (n=10). For a larger list, we can use function SIZE to obtain that
number, e.g.,
Suppose that we want to calculate the harmonic mean of the sample, defined
as




+ + +
= =
∑
=
n
n
k n
h
s s s n s n
s
1 1 1 1
1
1 1
1
2 1
1
L
.
To calculate this value we can follow this procedure:
1. Apply function INV () to list S:
2. Apply function ΣLIST() to the resulting list in1.