Calculating Sample Size and Margin of Error Table

Sample size for +/- 3%, +/- 5%, +/- 7%, and +/- 10% Precision Levels Where Confidence Level is 95% and P = .5

Sample size (n) for Precision (e) of:
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 samples.

Formula for calculating sample size:

√(.5) x (.5)  x 2            [where .5 denotes denotes the opinion in a community where half agree and half disagree]
        N

Online margin of sample size calculator: American Research Group, Inc

 

 

[Class] [Module 5]

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