Downloaded from https://www.everyspec.com AMCP 706-198 TABLE 24.21 SAMPIA SIZES REQUIRED TO DETECT PREISCRIND DIFFERENCES NTWIEN AVERAG&S WHEN THU SIGN OF THE DIFFERENCE IS IMPORTANT' The table entry is the sample size (N) required to detect with probability I - 0 that: (a) the average m of a new product exceeds that of a standard mn (b) the average m of a new product is less than that of a standard mo (c) the average of a specified product mA exceeds the average of another specified product ma. The standardized difference is d, where: (a) d - mr (b) d - U dr . MA a+frll, The standard deviations are assumed to be known, and N Is calculated from the following formula: 1."9.01 1- 9 .
00 .6 0 .7 0 , .8 0.9 .9 5 .9 9 .1 542 666 813 1004 1802 1578 2165 .2 166 167 2W 251 726 395 542 .4 SA 42 51 68 82 99 186 .6 16 10 21 28 37 44 61 .6 9 11 is to 21 25 84 1.0 6 7 9 11 14 16 22 1.6 4 5 6 7 10 11 16 1.4 3 4 5 6 7 9 12 !.6 8 8 4 4 6 7 9 1.6 2 a 8 4 5 5 7 2.0 2 2 3 8 4 4 6 3.0 1 1 1 2 2 2 a If we musit etimate v rrom our nample, and un. Student's 1, add 8 to the tabulated values to obtain the approximate required sample slie. (If we are comparing two product averMs, add 2 to the tsbulated values to obtain the required msi of each sample. For this ane, we must have d - . a -.
05 .50 .0 ,,o .0 .90 .95 .99,, .1 I 271 361 471 619 857 1083 1578 .2 68 91 118 155 215 271 396 .4 17 23 30 39 54 68 99 A .6 8 11 14 18 24 31 44 .8 5 6 8 10 14 17 25 1.0 3 4 5 7 9 11 16 1.2 2 3 4 5 6 8 11 1.4 2 2 a 4 5 6 9 1.6 2 2 2 a 4 5 7 1.8 1 2 2 P.2 3 4 5 2.0 1 1 2 2 3 3 4 3.0 1 1 1 1 1 2 2 if we must estimate e from otir sample, and use Student t, add 2 to the tabulated values to obtain the approximate required smtpie nle. (If we are comparing two product sveraget, add I to the tabulated values to obtain the required jige of each sample, For this can, we must have vA -6H)