Analysis of Means with Equal Sample Sizes
/****************************************************************/
/* S A S S A M P L E L I B R A R Y */
/* */
/* NAME: ANOMX1 */
/* TITLE: Analysis of Means with Equal Sample Sizes */
/* PRODUCT: QC */
/* SYSTEM: ALL */
/* KEYS: ANOM, Analysis of Means, */
/* PROCS: SHEWHART */
/* DATA: */
/* REF: L.S. Nelson (1983), 'Exact Critical Values for */
/* Use with the Analysis of Means'. Journal of Quality */
/* Technology 15, pp. 40-44. */
/* */
/* D.O. Fulenwider (1988), 'Using SAS Software for */
/* Analysis of Means', "SAS Users Group International: */
/* Proceedings of the Thirteenth Annual Conference, */
/* 1212-1219. */
/* */
/* NOTES: This sample program uses the anomh1 macro defined */
/* in sample program ANOMH1. Those statements must be */
/* submitted before this sample program. */
/* */
/****************************************************************/
data example1;
input aggregt $ 2 @;
do i = 1 TO 6;
input moisture @;
output;
end;
drop i;
cards;
1 551 457 450 731 499 632
2 595 580 508 583 633 517
3 639 615 511 573 648 677
4 417 449 517 438 415 555
5 563 631 522 613 656 679
;
proc shewhart data=example1;
xchart moisture*aggregt /
nochart
stddevs
smethod=rmsdf
outhistory=hist1
outlimits=lim1;
data hist1a;
set hist1 end=eof;
retain n;
if _n_ = 1 then do;
n=moisturen;
call symput('n',left(put(moisturen,4.)));
end;
if eof then do;
set lim1(keep=_stddev_);
mse=(_stddev_ * c4(n*_n_ - (_n_-1)))**2;
msedf=_n_*(n-1);
call symput('ntrt',left(put(_n_,4.)));
call symput('mse',left(put(mse,8.3)));
call symput('msedf',left(put(msedf,8.)));
end;
run;
/* NOTE: Alpha level is .05, halpha is calculated */
%anomh1(.05,&msedf,&ntrt);
data lim1a;
set lim1;
halpha=&halpha;
hdelta=&halpha*sqrt(&mse)*sqrt((&ntrt-1)/(&ntrt*&n));
_lclx_=_mean_-hdelta;
_uclx_=_mean_+hdelta;
_stddev_=sqrt(&mse);
_alpha_=.05;
run;
symbol1 v=none h=3 c=black w=20 f=;
title1 font=swiss h=1.5 c=black 'Analysis of Means';
title2 font=swiss h=.9 c=black 'Equal Sample Sizes';
proc shewhart history=hist1a limits=lim1a;
xchart moisture*aggregt/
stddevs
smethod=rmsdf
ct=black
cframe=tan
climits=black
ca=black
cout=orange
font=swiss
readalpha
noconnect
cneedles=green
nolegend
ucllabel='UDL'
lcllabel='LDL'
haxis=(' ' '1' '2' '3' '4' '5' ' ');
label moisturex= 'Moisture Absorption'
aggregt= 'Concrete Aggregate';
run;