Research Article

Confidence Intervals for the Coefficient of Variation in a Normal Distribution with a Known Population Mean

Table 3

The estimated coverage probabilities and expected lengths of 95% confidence intervals for the coefficient of variation in a normal distribution with a known population mean.

Coverage probabilitiesExpected lengths
MillerMcKayVangelApprox.ShortestEqual-tailedMillerMcKayVangelApprox.ShortestEqual-tailed

50.050.88290.95330.94400.95380.95040.95110.06610.07850.07620.10580.07580.0870
0.100.88270.95370.94570.95490.95010.95060.13330.16080.15440.21130.15130.1737
0.200.88470.95780.95080.95480.95000.95070.27560.36300.32820.42260.30260.3475
0.330.89040.96470.95990.95420.95010.95010.48800.89540.64980.69860.50010.5743
0.500.89340.97110.96560.95370.94870.94910.82761.37961.43331.05610.75610.8683
0.670.90420.97950.97210.95480.94950.95021.25501.57581.97911.41401.01241.1625

100.050.91150.95220.94400.95110.95020.94950.04510.04900.04780.05510.04800.0515
0.100.91250.95390.94600.95290.95100.95050.09120.09970.09680.11050.09620.1031
0.200.91560.95880.95220.95210.95060.94980.18810.21130.20230.22090.19240.2062
0.330.92010.96630.96200.95070.94990.94890.33110.40520.37180.36450.31740.3401
0.500.92810.97880.97510.95100.94920.95000.56060.97970.74150.55280.48140.5159
0.670.93720.98560.98120.95040.95000.94920.84701.75441.57760.73980.64420.6904

150.050.92440.95170.94430.95070.95060.94990.03660.03860.03770.04150.03800.0398
0.100.92500.95230.94460.94940.95010.94750.07370.07810.07610.08300.07600.0796
0.200.92940.95920.95370.95160.95090.95070.15200.16370.15840.16600.15210.1593
0.330.93240.96810.96340.95020.94930.94890.26690.30160.28610.27370.25080.2626
0.500.94180.98110.97830.95010.94900.94970.44950.59170.52670.41410.37940.3973
0.670.95280.98940.98620.94960.95100.94930.68191.33611.03060.55640.50970.5338

250.050.93560.95130.94580.95040.95000.95050.02810.02900.02840.03020.02870.0295
0.100.93380.95090.94520.94910.94810.94840.05660.05860.05730.06040.05740.0590
0.200.93830.95800.95270.94970.94950.94910.11670.12190.11880.12090.11490.1181
0.330.94530.97010.96640.95100.94970.95050.20430.21920.21180.19900.18920.1945
0.500.95750.98390.98160.95200.95160.95120.34560.40040.37830.30240.28750.2956
0.670.96510.99200.98990.95120.95030.95050.52050.71260.63820.40450.38450.3953

500.050.94000.95040.94580.95040.94880.94990.01980.02010.01970.02040.01990.0202
0.100.94310.95200.94730.94930.94910.94920.03980.04050.03980.04090.03990.0405
0.200.94790.95810.95340.94960.94910.94910.08190.08370.08210.08170.07970.0808
0.330.95810.96950.96690.95060.95100.95020.14370.14900.14570.13490.13160.1334
0.500.96860.98530.98340.95180.95120.95140.24200.26150.25380.20440.19940.2022
0.670.97760.99400.99270.95070.95060.95100.36520.42720.40890.27400.26730.2710

1000.050.94540.95020.94630.94960.94960.94920.01390.01400.01380.01410.01400.0141
0.100.94790.95280.94940.95110.95020.95070.02810.02830.02790.02830.02800.0282
0.200.95450.95900.95540.95000.95010.95010.05780.05840.05760.05660.05590.0563
0.330.96210.96970.96750.94930.94890.94910.10130.10340.10180.09340.09230.0929
0.500.97580.98440.98340.94890.94860.94880.17050.17890.17570.14160.13990.1408
0.670.98490.99460.99390.94950.94890.94920.25700.28400.27750.18960.18730.1886