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Sample Size Required to Achieve a Desired Confidence Level

(with proportion defective = 0.15)

p=0.15

Number of Failures

Confidence Levels

60%

80%

90%

95%

99%
0 6 10 17 20 30
1 14 20 26 30 43
2 21 29 36 40 55
3 28 37 44 50 55
4 35 45 52 59 76
5 42 52 60 68 86
6 49 60 69 77 94
7 56 68 72 86 103
8 63 75 85 94 112
9 70 82 93 102 120
10 76 90 100 110 130
11 83 97 108 118 138
12 90 105 117 127 148
13 97 112 124 135 157
14 104 119 132 143 165
15 111 127 140 150 173
16 118 134 147 159 182
17 125 141 155 167 190
18 132 149 162 175 198
19 138 156 170 182 207
20 145 162 178 190 215
22 159 178 193 206 230
24 173 192 208 220 248
26 186 206 222 236 264
28 200 220 237 250 279
30 213 235 252 267 296
35 247 270 289 304 336
40 281 306 325 342 375
45 315 341 361 379

408
50 349 377 398 411

447

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