Sample Size Calculator 1

Sample Size Calculator for a Single MeanSample size calculator for a single mean, for a given probability of error and delta

Alpha Error 0.05 Probability of not having the population mean included in the confidence intervalConfidence Interval 95% Probability of the population mean being located within the confidence intervalSample Standard Deviation 0.010 Baseline process standard deviationBeta Error 0.05 Probability of not being able to detect deltaPower 95% Probability of correctly detecting deltaDelta (accuracy of the estimate) 0.002 Accuracy with which the mean may be estimated (practical difference of interest)D ratio (Delta/Sigma) 0.2 If D-ratio is greater than 2 the sample size will always be 5One or two sided test (1,2) 2 If deviation in either direction is of interest use 2 and if deviation in only one direction is of interest specify 1.

Sample Size = 328

Delta Calculator for a Single Mean and a Known Sample SizeDelta is the accuracy with which the mean may be estimated for a given probability of error and sample size

Alpha Error 0.05 Probability of not having the population mean included in the confidence intervalConfidence Interval 95% Probability of the population mean being located within the confidence intervalSample Standard Deviation 0.010 Baseline process standard deviationBeta Error 0.05 Probability of not being able to detect deltaPower 95% Probability of correctly detecting deltaSample Size 328 Specify the sample size to be evaluatedOne or two sided test (1,2) 1 If deviation in either direction is of interest use 2 and if deviation in only one direction is of interest specify 1.Unit of Measure Mils

Delta = 0.002 Mean can be accurately determined plus or minus the delta indicated with a known probability of detection

Compare results to JMP 5.01Compare results to Minitab version 13.31

Sample size equations:

© TLC, 2003 Rev. 1.2

www.itl.nist.gov/div898/handbook/prc/section2/prc222.htm

www.dr-tom.com

Probability of not having the population mean included in the confidence intervalProbability of the population mean being located within the confidence intervalBaseline process standard deviationProbability of not being able to detect deltaProbability of correctly detecting deltaAccuracy with which the mean may be estimated (practical difference of interest)If D-ratio is greater than 2 the sample size will always be 5If deviation in either direction is of interest use 2 and if deviation in only one direction is of interest specify 1.

dfn

Delta is the accuracy with which the mean may be estimated for a given probability of error and sample size

Probability of not having the population mean included in the confidence intervalProbability of the population mean being located within the confidence intervalBaseline process standard deviationProbability of not being able to detect deltaProbability of correctly detecting deltaSpecify the sample size to be evaluatedIf deviation in either direction is of interest use 2 and if deviation in only one direction is of interest specify 1.

Mean can be accurately determined plus or minus the delta indicated with a known probability of detection

1.959964 1.967313 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245

1.644854 1.64957 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527

324.8678 327.0461 327.026 327.026 327.026 327.026 327.026 327.026 327.026

324 327 327 327 327 327 327 327 327325 328 328 328 328 328 328 328 328

1.967245 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245

1.649527 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527

327.026 327.026 327.026 327.026 327.026 327.026 327.026 327.026 327.026

327 327 327 327 327 327 327 327 327328 328 328 328 328 328 328 328 328

1.967245 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245

1.649527 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527

327.026 327.026 327.026 327.026 327.026 327.026 327.026 327.026 327.026

327 327 327 327 327 327 327 327 327328 328 328 328 328 328 328 328 328

1.967245 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245 1.967245

1.649527 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527 1.649527

327.026 327.026 327.026 327.026 327.026 327.026 327.026 327.026 327.026

327 327 327 327 327 327 327 327 327328 328 328 328 328 328 328 328 328

1.967245

1.649527

327.026 327.026

327328

Sample Size Calculator for a Single Sample Standard DeviationSample size calculator for a single standard deviation, for a given probability of error and delta

Alpha Error 0.05 Probability of not having the population standard deviation included in the confidence intervalConfidence Interval 95% Probability of the population standard deviation located within the confidence intervalBaseline Standard Deviation 0.006 Baseline standard deviation for a product or processsBeta Error 0.05 Probability of not being able to detect delta standard deviationPower 95% Probability of correctly detecting the delta standard deviationDelta (Change in the Standard Deviation) 0.006 Accuracy with which the standard deviation may be estimated (practical difference of interest)

Sample Size = 46 Number of units to be inspected or tested

* Warning sample sizes of >780 are not accurate due to Excel's limitation of the CHI Square Function

© TLC, 2003 Rev. 1.2

Reference NIST

www.dr-tom.comwww.itl.nist.gov/div898/handbook/prc/section2/prc232.htm

Sample Size Calculator for a Single Sample Standard Deviation

Probability of not having the population standard deviation included in the confidence intervalProbability of the population standard deviation located within the confidence intervalBaseline standard deviation for a product or processsProbability of not being able to detect delta standard deviationProbability of correctly detecting the delta standard deviationAccuracy with which the standard deviation may be estimated (practical difference of interest)

Number of units to be inspected or tested

* Warning sample sizes of >780 are not accurate due to Excel's limitation of the CHI Square Function k 2.00 1 1.920729 0.165776 11.644854 2.000 2 2.995732 0.223607 2

z beta 3 3.907364 0.271642 31.644854 4 4.743865 0.314602 4

5 5.535249 0.354096 56 6.295794 0.390884 67 7.03357 0.425393 78 7.753657 0.457896 89 8.459489 0.488584 9

10 9.153519 0.517599 1011 9.837569 0.545055 1112 10.51303 0.571046 1213 11.18102 0.595656 1314 11.8424 0.618958 1415 12.4979 0.641018 1516 13.14811 0.661899 1617 13.79356 0.681658 1718 14.43465 0.700349 1819 15.07176 0.718025 1920 15.70522 0.734735 2021 16.33529 0.750527 2122 16.96222 0.765444 2223 17.58623 0.77953 2324 18.20751 0.792827 2425 18.82624 0.805375 2526 19.44257 0.817211 2627 20.05664 0.828371 2728 20.66857 0.838891 2829 21.27848 0.848804 2930 21.88649 0.858141 3031 22.49267 0.866934 3132 23.09713 0.875211 3233 23.69994 0.883 3334 24.30118 0.890328 3435 24.90092 0.897219 35

36 25.49923 0.903698 3637 26.09616 0.909788 3738 26.69177 0.915511 3839 27.28611 0.920887 3940 27.87924 0.925935 4041 28.47119 0.930675 4142 29.06202 0.935124 4243 29.65176 0.939299 4344 30.24044 0.943216 4445 30.82812 0.94689 4546 31.41481 0.95033547 32.00056 0.95356548 32.58538 0.95659249 33.16932 0.95942950 33.7524 0.96208751 34.33465 0.96457652 34.91608 0.96690853 35.49673 0.9690954 36.07661 0.97113455 36.65575 0.97304656 37.23416 0.97483557 37.81187 0.97650958 38.3889 0.97807559 38.96526 0.9795460 39.54097 0.98090961 40.11605 0.98218962 40.69051 0.98338663 41.26436 0.98450464 41.83763 0.98554965 42.41032 0.98652566 42.98245 0.98743767 43.55404 0.98828968 44.12508 0.98908469 44.6956 0.98982770 45.26561 0.9905271 45.83512 0.99116772 46.40414 0.99177173 46.97267 0.99233474 47.54073 0.9928675 48.10834 0.9933576 48.67549 0.99380877 49.24219 0.99423478 49.80846 0.99463279 50.37431 0.99500380 50.93974 0.99534981 51.50475 0.99567182 52.06937 0.99597183 52.63359 0.99625184 53.19742 0.99651285 53.76087 0.99675586 54.32395 0.996981

87 54.88665 0.99719288 55.449 0.99738889 56.01099 0.99757190 56.57264 0.99774191 57.13393 0.997992 57.69489 0.99804893 58.25552 0.99818594 58.81583 0.99831395 59.37581 0.99843296 59.93547 0.99854297 60.49482 0.99864598 61.05387 0.99874199 61.61261 0.99883

100 62.17106 0.998913101 62.72921 0.998991102 63.28707 0.999062103 63.84465 0.999129104 64.40195 0.999191105 64.95898 0.999249106 65.51573 0.999302107 66.07221 0.999352108 66.62843 0.999398109 67.18439 0.999442110 67.74009 0.999482111 68.29554 0.999519112 68.85073 0.999553113 69.40568 0.999585114 69.96039 0.999615115 70.51485 0.999643116 71.06908 0.999669117 71.62307 0.999692118 72.17684 0.999715119 72.73037 0.999735120 73.28368 0.999754121 73.83676 0.999772122 74.38963 0.999789123 74.94228 0.999804124 75.49472 0.999818125 76.04694 0.999831126 76.59895 0.999844127 77.15076 0.999855128 77.70236 0.999866129 78.25376 0.999875130 78.80496 0.999884131 79.35597 0.999893132 79.90677 0.999901133 80.45739 0.999908134 81.00781 0.999915135 81.55805 0.999921136 82.1081 0.999927137 82.65797 0.999932

138 83.20765 0.999937139 83.75715 0.999942140 84.30648 0.999946141 84.85563 0.99995142 85.4046 0.999954143 85.9534 0.999957144 86.50203 0.99996145 87.05049 0.999963146 87.59878 0.999966147 88.14691 0.999968148 88.69487 0.999971149 89.24268 0.999973150 89.79032 0.999975151 90.3378 0.999977152 90.88512 0.999978153 91.43229 0.99998154 91.9793 0.999982155 92.52617 0.999983156 93.07288 0.999984157 93.61943 0.999985158 94.16585 0.999986159 94.71211 0.999987160 95.25823 0.999988161 95.8042 0.999989162 96.35003 0.99999163 96.89572 0.999991164 97.44127 0.999991165 97.98668 0.999992166 98.53195 0.999993167 99.07709 0.999993168 99.62209 0.999994169 100.167 0.999994170 100.7117 0.999995171 101.2563 0.999995172 101.8008 0.999995173 102.3451 0.999996174 102.8893 0.999996175 103.4334 0.999996176 103.9774 0.999997177 104.5212 0.999997178 105.0649 0.999997179 105.6085 0.999997180 106.152 0.999998181 106.6953 0.999998182 107.2385 0.999998183 107.7816 0.999998184 108.3246 0.999998185 108.8675 0.999998186 109.4102 0.999998187 109.9529 0.999999188 110.4954 0.999999

189 111.0378 0.999999190 111.5801 0.999999191 112.1223 0.999999192 112.6644 0.999999193 113.2064 0.999999194 113.7482 0.999999195 114.29 0.999999196 114.8316 0.999999197 115.3732 0.999999198 115.9146 0.999999199 116.4559 0.999999200 116.9971 0.999999201 117.5383 1202 118.0793 1203 118.6202 1204 119.161 1205 119.7017 1206 120.2423 1207 120.7829 1208 121.3233 1209 121.8636 1210 122.4038 1211 122.9439 1212 123.484 1213 124.0239 1214 124.5638 1215 125.1035 1216 125.6432 1217 126.1827 1218 126.7222 1219 127.2616 1220 127.8009 1221 128.3401 1222 128.8792 1223 129.4183 1224 129.9572 1225 130.4961 1226 131.0348 1227 131.5735 1228 132.1121 1229 132.6506 1230 133.1891 1231 133.7274 1232 134.2657 1233 134.8038 1234 135.3419 1235 135.8799 1236 136.4179 1237 136.9557 1238 137.4935 1239 138.0312 1

240 138.5688 1241 139.1064 1242 139.6438 1243 140.1812 1244 140.7185 1245 141.2557 1246 141.7929 1247 142.33 1248 142.867 1249 143.4039 1250 143.9408 1251 144.4775 1252 145.0142 1253 145.5509 1254 146.0874 1255 146.6239 1256 147.1603 1257 147.6967 1258 148.233 1259 148.7692 1260 149.3053 1261 149.8414 1262 150.3774 1263 150.9133 1264 151.4491 1265 151.9849 1266 152.5207 1267 153.0563 1268 153.5919 1269 154.1274 1270 154.6629 1271 155.1983 1272 155.7336 1273 156.2689 1274 156.8041 1275 157.3392 1276 157.8743 1277 158.4093 1278 158.9442 1279 159.4791 1280 160.0139 1281 160.5486 1282 161.0833 1283 161.618 1284 162.1525 1285 162.687 1286 163.2215 1287 163.7559 1288 164.2902 1289 164.8245 1290 165.3587 1

291 165.8928 1292 166.4269 1293 166.9609 1294 167.4949 1295 168.0288 1296 168.5627 1297 169.0965 1298 169.6302 1299 170.1639 1300 170.6976 1301 171.2311 1302 171.7646 1303 172.2981 1304 172.8315 1305 173.3649 1306 173.8982 1307 174.4314 1308 174.9646 1309 175.4977 1310 176.0308 1311 176.5639 1312 177.0968 1313 177.6298 1314 178.1626 1315 178.6954 1316 179.2282 1317 179.7609 1318 180.2936 1319 180.8262 1320 181.3588 1321 181.8913 1322 182.4237 1323 182.9561 1324 183.4885 1325 184.0208 1326 184.553 1327 185.0853 1328 185.6174 1329 186.1495 1330 186.6816 1331 187.2136 1332 187.7456 1333 188.2775 1334 188.8093 1335 189.3412 1336 189.8729 1337 190.4047 1338 190.9363 1339 191.468 1340 191.9996 1341 192.5311 1

342 193.0626 1343 193.594 1344 194.1254 1345 194.6568 1346 195.1881 1347 195.7194 1348 196.2506 1349 196.7818 1350 197.3129 1351 197.844 1352 198.375 1353 198.906 1354 199.437 1355 199.9679 1356 200.4987 1357 201.0295 1358 201.5603 1359 202.0911 1360 202.6218 1361 203.1524 1362 203.683 1363 204.2136 1364 204.7441 1365 205.2746 1366 205.805 1367 206.3354 1368 206.8658 1369 207.3961 1370 207.9264 1371 208.4566 1372 208.9868 1373 209.5169 1374 210.047 1375 210.5771 1376 211.1071 1377 211.6371 1378 212.1671 1379 212.697 1380 213.2269 1381 213.7567 1382 214.2865 1383 214.8162 1384 215.346 1385 215.8756 1386 216.4053 1387 216.9349 1388 217.4644 1389 217.994 1390 218.5234 1391 219.0529 1392 219.5823 1

393 220.1117 1394 220.641 1395 221.1703 1396 221.6996 1397 222.2288 1398 222.758 1399 223.2871 1400 223.8162 1401 224.3453 1402 224.8744 1403 225.4034 1404 225.9323 1405 226.4613 1406 226.9902 1407 227.519 1408 228.0478 1409 228.5766 1410 229.1054 1411 229.6341 1412 230.1628 1413 230.6914 1414 231.2201 1415 231.7486 1416 232.2772 1417 232.8057 1418 233.3342 1419 233.8626 1420 234.391 1421 234.9194 1422 235.4477 1423 235.9761 1424 236.5043 1425 237.0326 1426 237.5608 1427 238.089 1428 238.6171 1429 239.1452 1430 239.6733 1431 240.2013 1432 240.7293 1433 241.2573 1434 241.7853 1435 242.3132 1436 242.8411 1437 243.3689 1438 243.8967 1439 244.4245 1440 244.9523 1441 245.48 1442 246.0077 1443 246.5353 1

444 247.063 1445 247.5906 1446 248.1181 1447 248.6457 1448 249.1732 1449 249.7007 1450 250.2281 1451 250.7555 1452 251.2829 1453 251.8103 1454 252.3376 1455 252.8649 1456 253.3921 1457 253.9194 1458 254.4466 1459 254.9737 1460 255.5009 1461 256.028 1462 256.5551 1463 257.0821 1464 257.6092 1465 258.1362 1466 258.6631 1467 259.1901 1468 259.717 1469 260.2439 1470 260.7707 1471 261.2975 1472 261.8243 1473 262.3511 1474 262.8778 1475 263.4046 1476 263.9312 1477 264.4579 1478 264.9845 1479 265.5111 1480 266.0377 1481 266.5642 1482 267.0907 1483 267.6172 1484 268.1437 1485 268.6701 1486 269.1965 1487 269.7229 1488 270.2493 1489 270.7756 1490 271.3019 1491 271.8282 1492 272.3544 1493 272.8806 1494 273.4068 1

495 273.933 1496 274.4591 1497 274.9852 1498 275.5113 1499 276.0374 1500 276.5634 1501 277.0894 1502 277.6154 1503 278.1413 1504 278.6673 1505 279.1932 1506 279.7191 1507 280.2449 1508 280.7707 1509 281.2965 1510 281.8223 1511 282.3481 1512 282.8738 1513 283.3995 1514 283.9252 1515 284.4508 1516 284.9764 1517 285.502 1518 286.0276 1519 286.5532 1520 287.0787 1521 287.6042 1522 288.1297 1523 288.6551 1524 289.1806 1525 289.706 1526 290.2313 1527 290.7567 1528 291.282 1529 291.8073 1530 292.3326 1531 292.8579 1532 293.3831 1533 293.9083 1534 294.4335 1535 294.9587 1536 295.4838 1537 296.0089 1538 296.534 1539 297.0591 1540 297.5842 1541 298.1092 1542 298.6342 1543 299.1592 1544 299.6841 1545 300.2091 1

546 300.734 1547 301.2589 1548 301.7837 1549 302.3086 1550 302.8334 1551 303.3582 1552 303.883 1553 304.4077 1554 304.9324 1555 305.4571 1556 305.9818 1557 306.5065 1558 307.0311 1559 307.5558 1560 308.0803 1561 308.6049 1562 309.1295 1563 309.654 1564 310.1785 1565 310.703 1566 311.2275 1567 311.7519 1568 312.2763 1569 312.8007 1570 313.3251 1571 313.8495 1572 314.3738 1573 314.8981 1574 315.4224 1575 315.9467 1576 316.4709 1577 316.9952 1578 317.5194 1579 318.0436 1580 318.5677 1581 319.0919 1582 319.616 1583 320.1401 1584 320.6642 1585 321.1883 1586 321.7123 1587 322.2363 1588 322.7603 1589 323.2843 1590 323.8083 1591 324.3322 1592 324.8561 1593 325.38 1594 325.9039 1595 326.4278 1596 326.9516 1

597 327.4754 1598 327.9992 1599 328.523 1600 329.0468 1601 329.5705 1602 330.0942 1603 330.618 1604 331.1416 1605 331.6653 1606 332.1889 1607 332.7126 1608 333.2362 1609 333.7597 1610 334.2833 1611 334.8069 1612 335.3304 1613 335.8539 1614 336.3774 1615 336.9009 1616 337.4243 1617 337.9477 1618 338.4711 1619 338.9945 1620 339.5179 1621 340.0413 1622 340.5646 1623 341.0879 1624 341.6112 1625 342.1345 1626 342.6578 1627 343.181 1628 343.7042 1629 344.2274 1630 344.7506 1631 345.2738 1632 345.7969 1633 346.3201 1634 346.8432 1635 347.3663 1636 347.8894 1637 348.4124 1638 348.9355 1639 349.4585 1640 349.9815 1641 350.5045 1642 351.0274 1643 351.5504 1644 352.0733 1645 352.5962 1646 353.1191 1647 353.642 1

648 354.1649 1649 354.6877 1650 355.2106 1651 355.7334 1652 356.2562 1653 356.7789 1654 357.3017 1655 357.8244 1656 358.3472 1657 358.8699 1658 359.3925 1659 359.9152 1660 360.4379 1661 360.9605 1662 361.4831 1663 362.0057 1664 362.5283 1665 363.0509 1666 363.5734 1667 364.096 1668 364.6185 1669 365.141 1670 365.6635 1671 366.1859 1672 366.7084 1673 367.2308 1674 367.7532 1675 368.2756 1676 368.798 1677 369.3204 1678 369.8427 1679 370.3651 1680 370.8874 1681 371.4097 1682 371.932 1683 372.4542 1684 372.9765 1685 373.4987 1686 374.0209 1687 374.5432 1688 375.0653 1689 375.5875 1690 376.1097 1691 376.6318 1692 377.1539 1693 377.676 1694 378.1981 1695 378.7202 1696 379.2423 1697 379.7643 1698 380.2863 1

699 380.8083 1700 381.3303 1701 381.8523 1702 382.3743 1703 382.8962 1704 383.4182 1705 383.9401 1706 384.462 1707 384.9839 1708 385.5057 1709 386.0276 1710 386.5494 1711 387.0713 1712 387.5931 1713 388.1149 1714 388.6366 1715 389.1584 1716 389.6802 1717 390.2019 1718 390.7236 1719 391.2453 1720 391.767 1721 392.2887 1722 392.8103 1723 393.332 1724 393.8536 1725 394.3752 1726 394.8968 1727 395.4184 1728 395.94 1729 396.4615 1730 396.983 1731 397.5046 1732 398.0261 1733 398.5476 1734 399.0691 1735 399.5905 1736 400.112 1737 400.6334 1738 401.1548 1739 401.6762 1740 402.1976 1741 402.719 1742 403.2404 1743 403.7617 1744 404.283 1745 404.8044 1746 405.3257 1747 405.847 1748 406.3682 1749 406.8895 1

750 407.4108 1751 407.932 1752 408.4532 1753 408.9744 1754 409.4956 1755 410.0168 1756 410.538 1757 411.0591 1758 411.5802 1759 412.1014 1760 412.6225 1761 413.1436 1762 413.6646 1763 414.1857 1764 414.7068 1765 415.2278 1766 415.7488 1767 416.2698 1768 416.7908 1769 417.3118 1770 417.8328 1771 418.3538 1772 418.8747 1773 419.3956 1774 419.9165 1775 420.4374 1776 420.9583 1777 421.4792 1778 422.0001 1779 422.5209 1

Sample Size Calculator for Proportion DefectiveSample size calculator the proportion defective, for a given probability of error and delta

Alpha Error 0.05 Probability of not having the population proportion defective included in the confidence intervalConfidence Interval 95% Probability of the population proportion defective being located within the confidence intervalBaseline Proportion Defective 0.20 Baseline population proportion defective, if unknown use .5 or best estimateBeta Error 0.10 Probability of not being able to detect deltaPower 90% Probability of correctly detecting deltaDelta (change in proportion defective) 0.10 Accuracy with which the proportion defective may be estimated (practical difference of interest)One or two sided (1,2) 2 If deviation in either direction is of interest use 2 and if deviation in only one direction is of interest specify 1.

Sample Size = 168 Sample size for the test

Sample size equations 1.959964 1.6448541.281552

Two sided 137 One sided 168 Two sided

One sided

Reference NIST

Compare results to Minitab version 13.31

Upper Confidence Interval for Sample Size assuming Zero DefectiveSample Size Upper 95% CI Observed Failure Rate=0

5 45.05%10 25.89%15 18.10%20 13.91%30 9.50%40 7.22%50 5.82%60 4.87%70 4.19%80 3.68%90 3.27%

100 2.95%125 2.37%150 1.98%175 1.70%200 1.49%300 0.99%400 0.75%500 0.60%

www.itl.nist.gov/div898/handbook/prc/section2/prc242.htm

0 100 200 300 400 500 6000.00%

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© TLC, 2003 Rev. 1.2www.dr-tom.com

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Upper Confidence Interval for Sample Size assuming Zero Defective

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Probability of not having the population proportion defective included in the confidence intervalProbability of the population proportion defective being located within the confidence intervalBaseline population proportion defective, if unknown use .5 or best estimateProbability of not being able to detect deltaProbability of correctly detecting deltaAccuracy with which the proportion defective may be estimated (practical difference of interest)If deviation in either direction is of interest use 2 and if deviation in only one direction is of interest specify 1.

Upper Confidence Interval for Sample Size assuming Zero DefectiveObserved Failure Rate=0

0 100 200 300 400 500 6000.00%

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Sample Size Calculator for Defects per Unit (DPU)Sample size calculator for estimating the defect density, for a given probability of error and delta

Alpha Error 0.05 Probability of not having the population DPU included in the confidence intervalConfidence Interval 95% Probability of the population DPU located within the confidence intervalBaseline Defects per Unit (DPU) 0.010 Baseline defect per unit for a product or processsBeta Error 0.05 Probability of not being able to detect delta DPUPower 95% Probability of correctly detecting delta DPUDelta (Change in the DPU) 0.050 Accuracy with which the DPU may be estimated (practical difference of interest)

Sample Size = 129 Number of units to be inspected or tested

Reference NIST

© TLC, 2003 Rev. 1.2www.dr-tom.comhttp://www.itl.nist.gov/div898/handbook/prc/section2/prc25.htm

Sample size calculator for estimating the defect density, for a given probability of error and delta

Probability of not having the population DPU included in the confidence intervalProbability of the population DPU located within the confidence intervalBaseline defect per unit for a product or processsProbability of not being able to detect delta DPUProbability of correctly detecting delta DPUAccuracy with which the DPU may be estimated (practical difference of interest)

Number of units to be inspected or tested

z alpha k1.644854 6.000

z beta1.644854