OPTIONS LINESIZE=70;
TITLE1 'MEANS - another Univariate Statistics';
DATA VIRUS; 
/* @@ means a loop in reading input variable sequence */
INPUT DILUTION $ COMPOUND $ TIME @@;
   IF DILUTION='A' THEN DL=1;
   ELSE IF DILUTION='B' THEN DL=2;
   ELSE IF DILUTION='C' THEN DL=4;
CARDS;
A PA 87  A PA 90
A PM 82  A PM 71
A UN 72  A UN 77
B PA 79  B PA 80
B PM 73  B PM 72
B UN 70  B UN 66
C PA 77  C PA 81
C PM 72  C PM 68
C UN 62  C UN 61
;
RUN;

PROC SORT; 
   BY COMPOUND;
RUN;

PROC MEANS N MEAN STD STDERR SUM VAR MIN MAX CV CSS USS
	    RANGE NMISS;
    BY COMPOUND;

/* N           = No. of nonmissing obs.                 */
/* STD         = Std. Dev.                              */
/* STDERR      = Std. error of mean, s/sq(n)            */
/* SUM         = Weighted sum                           */
/* VAR         = variance, s^2                          */
/* MIN & MAX   = minimum and Maximum                    */
/* CV          = % coeff. of variation, 100x(s/xbar)    */
/* SCC         = sum of sqares corrected for the mean   */
/* USS         = uncorrected sum of sqares              */
/* RANGE       = MAX-MIN                                */
/* NMISS       = no. of missing obs.                    */
RUN;

PROC MEANS NOPRINT;
   VAR TIME;
   BY COMPOUND;
   OUTPUT OUT=OUTA MEAN=M STD=S N=COUNT;
RUN;
   
PROC PRINT;
RUN;