Original Program from program editor.
****************************************************; *** Steele & Torrie (1980) Table 5.2 ***; *** Percent digestability of corn silage was ***; *** examined for sheep and steers. ***; *** ***; ****************************************************; options ps=61 ls=64 nocenter nodate nonumber; TITLE1 'Two sample t-tests'; data silage; infile cards missover; TITLE2 'Percent digestability of corn silage'; LABEL animal = 'Type of animal tested'; LABEL percent = 'Percent digestability'; input sheep steers; animal = 'Sheep '; percent = sheep; output; animal = 'Steers'; percent = steers; output; cards; run; 57.8 64.2 56.2 58.7 61.9 63.1 54.4 62.5 53.6 59.8 56.4 59.2 53.2 ; proc print data=silage; var animal percent; TITLE3 'Raw data listing'; run; proc ttest data=silage; class animal; var percent; TITLE3 'PROC TTEST results'; run; *****************************************************; *** Steele & Torrie (1980) Table 5.6 ***; *** Percent fine gravel found in surface soils. ***; *** Data from a study comparing characteristics ***; *** of soil catagorized as "good" or "poor". ***; *****************************************************; options ps=61 ls=78 nocenter nodate nonumber; TITLE1 'Two sample t-tests'; data dirt; infile cards missover; TITLE2 'Percent fine gravel in surface soils'; LABEL soilqual = 'Soil quality evaluation'; LABEL percent = 'Percent fine gravel'; input good poor; soilqual = 'good '; percent = good; output; soilqual = 'poor'; percent = poor; output; cards; run; 5.9 7.6 3.8 0.4 6.5 1.1 18.3 3.2 18.2 6.5 16.1 4.1 7.6 4.7 ; proc print data=dirt; var soilqual percent; TITLE3 'Raw data listing'; run; proc ttest data=dirt; class soilqual; var percent; TITLE3 'PROC TTEST results'; run; *******************************************************; *** Steele & Torrie (1980) Exercise 5.5.6 ***; *** The weights in grams of 10 male and 10 female ***; *** juvenile ring-necked pheasants trapped in ***; *** January in Wisconsin are given. Test the Ho ***; *** that males were 350 grams heavier than females. ***; *******************************************************; options ps=61 ls=78 nocenter nodate nonumber; TITLE1 'Two sample t-tests'; data birds; infile cards missover; TITLE2 'Weight in gms of male & female pheasants'; LABEL sex = 'Sex of pheasant'; LABEL weight = 'Weight in grams'; input sex $ weight; if sex eq 'Male' then AdjWT = Weight - 350; else AdjWT = weight; cards; run; Female 1061 Female 1065 Female 1092 Female 1017 Female 1021 Female 1138 Female 1143 Female 1094 Female 1270 Female 1028 Male 1293 Male 1380 Male 1614 Male 1497 Male 1340 Male 1643 Male 1466 Male 1627 Male 1383 Male 1711 ; proc print data=birds; var sex weight adjwt; TITLE3 'Raw data listing'; run; proc ttest data=birds H0=-350; class sex; var weight; TITLE3 'PROC TTEST results specifying a difference'; run; proc ttest data=birds; class sex; var adjwt; TITLE3 'PROC TTEST results on adjusted values'; run;
Below is output from the SAS log (bold) and output from the SAS Output window.
1 ****************************************************; 2 *** Steele & Torrie (1980) Table 5.2 ***; 3 *** Percent digestability of corn silage was ***; 4 *** examined for sheep and steers. ***; 5 *** ***; 6 ****************************************************; 7 options ps=61 ls=64 nocenter nodate nonumber; 8 TITLE1 'Two sample t-tests'; 9 10 11 data silage; infile cards missover; 12 TITLE2 'Percent digestability of corn silage'; 13 LABEL animal = 'Type of animal tested'; 14 LABEL percent = 'Percent digestability'; 15 input sheep steers; 16 animal = 'Sheep '; percent = sheep; output; 17 animal = 'Steers'; percent = steers; output; 18 cards; NOTE: The data set WORK.SILAGE has 14 observations and 4 variables. NOTE: DATA statement used (Total process time): real time 0.03 seconds cpu time 0.03 seconds 18 ! run; 26 ; 27 proc print data=silage; var animal percent; 28 TITLE3 'Raw data listing'; 29 run; NOTE: There were 14 observations read from the data set WORK.SILAGE. NOTE: The PROCEDURE PRINT printed page 1. NOTE: PROCEDURE PRINT used (Total process time): real time 0.01 seconds cpu time 0.01 seconds Two sample t-tests Percent digestability of corn silage Raw data listing Obs animal percent 1 Sheep 57.8 2 Steers 64.2 3 Sheep 56.2 4 Steers 58.7 5 Sheep 61.9 6 Steers 63.1 7 Sheep 54.4 8 Steers 62.5 9 Sheep 53.6 10 Steers 59.8 11 Sheep 56.4 12 Steers 59.2 13 Sheep 53.2 14 Steers . 30 proc ttest data=silage; class animal; var percent; 31 TITLE3 'PROC TTEST results'; 32 run; NOTE: There were 14 observations read from the data set WORK.SILAGE. NOTE: The PROCEDURE TTEST printed page 2. NOTE: PROCEDURE TTEST used (Total process time): real time 0.00 seconds cpu time 0.00 seconds Two sample t-tests Percent digestability of corn silage PROC TTEST results The TTEST Procedure Statistics Lower CL Upper CL Variable animal N Mean Mean Mean percent Sheep 7 53.437 56.214 58.991 percent Steers 6 58.834 61.25 63.666 percent Diff (1-2) -8.35 -5.036 -1.721 Statistics Lower CL Upper CL Variable animal Std Dev Std Dev Std Dev Std Err percent Sheep 1.9348 3.0025 6.6116 1.1348 percent Steers 1.4369 2.302 5.6458 0.9398 percent Diff (1-2) 1.9174 2.7066 4.5955 1.5058 Statistics Variable animal Minimum Maximum percent Sheep 53.2 61.9 percent Steers 58.7 64.2 percent Diff (1-2) T-Tests Variable Method Variances DF t Value Pr > |t| percent Pooled Equal 11 -3.34 0.0065 percent Satterthwaite Unequal 10.9 -3.42 0.0058 Equality of Variances Variable Method Num DF Den DF F Value Pr > F percent Folded F 6 5 1.70 0.5764 36 ***************************************************** ; 37 *** Steele & Torrie (1980) Table 5.6 *** ; 38 *** Percent fine gravel found in surface soils. *** ; 39 *** Data from a study comparing characteristics *** ; 40 *** of soil catagorized as "good" or "poor". *** ; 41 ***************************************************** ; 42 options ps=61 ls=78 nocenter nodate nonumber; 43 TITLE1 'Two sample t-tests'; 44 45 data dirt; infile cards missover; 46 TITLE2 'Percent fine gravel in surface soils'; 47 LABEL soilqual = 'Soil quality evaluation'; 48 LABEL percent = 'Percent fine gravel'; 49 input good poor; 50 soilqual = 'good '; percent = good; output; 51 soilqual = 'poor'; percent = poor; output; 52 cards; NOTE: The data set WORK.DIRT has 14 observations and 4 variables. NOTE: DATA statement used (Total process time): real time 0.01 seconds cpu time 0.00 seconds 52 ! run; 60 ; 61 proc print data=dirt; var soilqual percent; 62 TITLE3 'Raw data listing'; 63 run; NOTE: There were 14 observations read from the data set WORK.DIRT. NOTE: The PROCEDURE PRINT printed page 3. NOTE: PROCEDURE PRINT used (Total process time): real time 0.01 seconds cpu time 0.01 seconds Two sample t-tests Percent fine gravel in surface soils Raw data listing Obs soilqual percent 1 good 5.9 2 poor 7.6 3 good 3.8 4 poor 0.4 5 good 6.5 6 poor 1.1 7 good 18.3 8 poor 3.2 9 good 18.2 10 poor 6.5 11 good 16.1 12 poor 4.1 13 good 7.6 14 poor 4.7 64 proc ttest data=dirt; class soilqual; var percent; 65 TITLE3 'PROC TTEST results'; 66 run; NOTE: There were 14 observations read from the data set WORK.DIRT. NOTE: The PROCEDURE TTEST printed page 4. NOTE: PROCEDURE TTEST used (Total process time): real time 0.00 seconds cpu time 0.00 seconds Two sample t-tests Percent fine gravel in surface soils PROC TTEST results The TTEST Procedure Statistics Lower CL Upper CL Lower CL Variable soilqual N Mean Mean Mean Std Dev Std Dev percent good 7 5.0559 10.914 16.773 4.0819 6.3344 percent poor 7 1.5048 3.9429 6.3809 1.6987 2.6362 percent Diff (1-2) 1.3212 6.9714 12.622 3.4789 4.8515 Statistics Upper CL Variable soilqual Std Dev Std Err Minimum Maximum percent good 13.949 2.3942 3.8 18.3 percent poor 5.8051 0.9964 0.4 7.6 percent Diff (1-2) 8.0086 2.5932 T-Tests Variable Method Variances DF t Value Pr > |t| percent Pooled Equal 12 2.69 0.0197 percent Satterthwaite Unequal 8.02 2.69 0.0275 Equality of Variances Variable Method Num DF Den DF F Value Pr > F percent Folded F 6 6 5.77 0.0509 71 *******************************************************; 72 *** Steele & Torrie (1980) Exercise 5.5.6 ***; 73 *** The weights in grams of 10 male and 10 female ***; 74 *** juvenile ring-necked pheasants trapped in ***; 75 *** January in Wisconsin are given. Test the Ho ***; 76 *** that males were 350 grams heavier than females. ***; 77 *******************************************************; 78 options ps=61 ls=78 nocenter nodate nonumber; 79 TITLE1 'Two sample t-tests'; 80 81 data birds; infile cards missover; 82 TITLE2 'Weight in gms of male & female pheasants'; 83 LABEL sex = 'Sex of pheasant'; 84 LABEL weight = 'Weight in grams'; 85 input sex $ weight; 86 if sex eq 'Male' then AdjWT = Weight - 350; 87 else AdjWT = weight; 88 cards; NOTE: The data set WORK.BIRDS has 20 observations and 3 variables. NOTE: DATA statement used (Total process time): real time 0.01 seconds cpu time 0.01 seconds 88 ! run; 109 ; 110 proc print data=birds; var sex weight adjwt; 111 TITLE3 'Raw data listing'; 112 run; NOTE: There were 20 observations read from the data set WORK.BIRDS. NOTE: The PROCEDURE PRINT printed page 5. NOTE: PROCEDURE PRINT used (Total process time): real time 0.00 seconds cpu time 0.00 seconds Two sample t-tests Weight in gms of male & female pheasants Raw data listing Adj Obs sex weight WT 1 Female 1061 1061 2 Female 1065 1065 3 Female 1092 1092 4 Female 1017 1017 5 Female 1021 1021 6 Female 1138 1138 7 Female 1143 1143 8 Female 1094 1094 9 Female 1270 1270 10 Female 1028 1028 11 Male 1293 943 12 Male 1380 1030 13 Male 1614 1264 14 Male 1497 1147 15 Male 1340 990 16 Male 1643 1293 17 Male 1466 1116 18 Male 1627 1277 19 Male 1383 1033 20 Male 1711 1361 113 114 proc ttest data=birds H0=-350; class sex; var weight; 115 TITLE3 'PROC TTEST results specifying a difference'; 116 run; NOTE: There were 20 observations read from the data set WORK.BIRDS. NOTE: The PROCEDURE TTEST printed page 6. NOTE: PROCEDURE TTEST used (Total process time): real time 0.00 seconds cpu time 0.00 seconds Two sample t-tests Weight in gms of male & female pheasants PROC TTEST results specifying a difference The TTEST Procedure Statistics Lower CL Upper CL Lower CL Variable sex N Mean Mean Mean Std Dev Std Dev weight Female 10 1038.1 1092.9 1147.7 52.709 76.63 weight Male 10 1391 1495.4 1599.8 100.36 145.9 weight Diff (1-2) -512 -402.5 -293 88.053 116.53 Statistics Upper CL Variable sex Std Dev Std Err Minimum Maximum weight Female 139.9 24.232 1017 1270 weight Male 266.36 46.138 1293 1711 weight Diff (1-2) 172.33 52.115 T-Tests Variable Method Variances DF t Value Pr > |t| weight Pooled Equal 18 -1.01 0.3271 weight Satterthwaite Unequal 13.6 -1.01 0.3313 Equality of Variances Variable Method Num DF Den DF F Value Pr > F weight Folded F 9 9 3.63 0.0686 117 proc ttest data=birds; class sex; var adjwt; 118 TITLE3 'PROC TTEST results on adjusted values'; 119 run; NOTE: There were 20 observations read from the data set WORK.BIRDS. NOTE: The PROCEDURE TTEST printed page 7. NOTE: PROCEDURE TTEST used (Total process time): real time 0.00 seconds cpu time 0.00 seconds NOTE: SAS Institute Inc., SAS Campus Drive, Cary, NC USA 27513-2414 NOTE: The SAS System used: real time 0.59 seconds cpu time 0.24 seconds Two sample t-tests Weight in gms of male & female pheasants PROC TTEST results on adjusted values The TTEST Procedure Statistics Lower CL Upper CL Lower CL Variable sex N Mean Mean Mean Std Dev Std Dev AdjWT Female 10 1038.1 1092.9 1147.7 52.709 76.63 AdjWT Male 10 1041 1145.4 1249.8 100.36 145.9 AdjWT Diff (1-2) -162 -52.5 56.989 88.053 116.53 Statistics Upper CL Variable sex Std Dev Std Err Minimum Maximum AdjWT Female 139.9 24.232 1017 1270 AdjWT Male 266.36 46.138 943 1361 AdjWT Diff (1-2) 172.33 52.115 T-Tests Variable Method Variances DF t Value Pr > |t| AdjWT Pooled Equal 18 -1.01 0.3271 AdjWT Satterthwaite Unequal 13.6 -1.01 0.3313 Equality of Variances Variable Method Num DF Den DF F Value Pr > F AdjWT Folded F 9 9 3.63 0.0686