Weighted Mean (Prog ?)

[John H Meyers]

In article <333A17...@cstone.net>, Chris Myers <cmy...@cstone.net> writes:

> Is there a program available or can someone tell tell me how to
> program my 48GX to calculate GPA?

If you mean "Grade Point Average," which is generally a Weighted Mean
of numeric grades (or grade equivalents), with the number of credits
for each course being the weight, you can use the program below.

First, fill in the Statistics Matrix, using any of the built-in
Statistics applications, entering each numeric grade equivalent
into column 1, and the corresponding number of credits into column 2,
then press the key for the program below. which returns three results:

o Weighted Mean of column 1, using weights from column 2
o Standard Deviation (estimated from sample entered)
o Standard Deviation (of population actually entered)

If you select an "X-Column" and/or a "Y-Column" different from
the defaults (columns 1 and 2), then the results reflect the
values in the "X-Column" using weights from the "Y-Column"

For anyone who remembers, the program below is a slight improvement
upon the previously-posted WEIGHT3, in that it no longer requires
SigmaPAR to exist (the standard default columns are assumed if not).

Credits: Bob Wheeler <bwhe...@echip.com> supplied the algorithm.

%%HP: T(3); @ \-> is right-arrow, \v/ is Square Root, \GS is Sigma
@ WMS - Weighted Mean and Standard Deviation, HP48G/GX
@ Stack diagram: ( SigmaDAT and SigmaPAR ) --> Mean, SDev(S), SDev(P)
@ If SigmaPAR does not exist, then
@ Col 1 (XCOL) is value and Col 2 (YCOL) is weight, by default
\<< '\GSPAR' DUP VTYPE 0 < { DROP 1 2 } { RCL 1 2 SUB EVAL } IFTE
0 0 DUP2 \-> x f w d m v
\<< RCL\GS x COL- SWAP DROP ARRY\-> EVAL \->LIST
RCL\GS f COL- SWAP DROP ARRY\-> EVAL \->LIST
2 \<< DUP2 'w' STO+ m - * DUP 'd' STO
w / 'm' STO+ m - d * 'v' STO+ \>> DOLIST
m v w DUP2 1 - / \v/ ROT ROT / \v/
\>> \>>

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With best wishes from: John H Meyers <jhme...@mum.edu>