There are FOUR (4) sources for calculating a sample size listed below.
1
Sample size for +/- 3%, +/- 5%, +/- 7%, and +/- 10% Precision Levels Where Confidence Level is 95% and P = .5
Always round UP when selecting your sample size. |
Margin of Error Table
Sample size (n) for Precision (e) of: |
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Size of Population | +/- 3% | +/- 5% | +/- 7% | +/- 10% |
500 | a | 222 | 145 | 83 |
600 | a | 240 | 152 | 86 |
700 | a | 255 | 158 | 88 |
800 | a | 267 | 163 | 89 |
900 | a | 277 | 166 | 90 |
1,000 | a | 286 | 169 | 91 |
2,000 | 714 | 333 | 185 | 95 |
3,000 | 811 | 353 | 191 | 97 |
4,000 | 870 | 364 | 194 | 98 |
5,000 | 909 | 370 | 196 | 98 |
6,000 | 938 | 375 | 197 | 98 |
7,000 | 959 | 378 | 198 | 99 |
8,000 | 976 | 381 | 199 | 99 |
9,000 | 989 | 383 | 200 | 99 |
10,000 | 1,000 | 385 | 200 | 99 |
15,000 | 1,034 | 390 | 201 | 99 |
20,000 | 1,053 | 392 | 204 | 100 |
25,000 | 1,064 | 394 | 204 | 100 |
50,000 | 1,087 | 397 | 204 | 100 |
100,000 | 1,099 | 398 | 204 | 100 |
Over 100,000 | 1,111 | 400 | 204 | 100 |
a - Assumption of normal approximation is poor (Yamane, 1967). The entire population should be sampled.
2
Online margin of sample size calculator: Creative Research Systems
3
Online margin of sample size calculator: American Research Group, Inc
4
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