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. Author manuscript; available in PMC: 2016 Mar 15.
Published in final edited form as: J Appl Stat. 2012 Nov 5;40(2):311–319. doi: 10.1080/02664763.2012.740629

Table 6.

Behavior of the Wald confidence interval width WW as compared to the fixed value w0 at π0 = 0.975 and α = 0.05.

Sample size w0
P(WW<w0|π0=0.975)
E(WW|π0=0.975)
n* CPn
CPn
10 0.1935 0.7763 0.0864 NAb 0.2256 NAb
11 0.1845 0.7569 0.0862 NAb 0.2428 NAb
100 0.0612 0.5422 0.0565 80 0.9163 0.8635
101 0.0609 0.5357 0.0563 81 0.9180 0.8664
200 0.0433 0.4383 0.0420 187 0.8724 0.9410
201 0.0432 0.6115 0.0419 188 0.8740 0.9477
1000 0.0194 0.4724 0.0193 989 0.9497 0.9481
1001 0.0193 0.5509 0.0192 990 0.9287 0.9488
2000 0.0137 0.4805 0.0136 1989 0.9397 0.9500
2001 0.0137 0.5361 0.0136 1990 0.9393 0.9508

Notes: n*, suggested sample size based on E(WW|π0=0.975)>w0; CPn, coverage probability for sample size n; CPn, coverage probability for sample size n*;

b

, n* and CPn are not attainable for the corresponding sample size.