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Table 33 Performance of tolerance intervals based on lognormal distribution when the true distribution is gamma (G: Lognormal; F: Gamma)

From: Tolerance intervals in statistical software and robustness under model misspecification

  

n = 10

n = 25

n = 50

n = 100

n = 10

n = 25

n = 50

n = 100

  

ρ= 0.9

   

ρ= 0.95

   

α = 0.01

\(\hat {\alpha }\)

0.0107

0.0102

0.0110

0.0101

0.0123

0.0124

0.0139

0.0132

 

\(\hat {\rho }\)

0.9912

0.9768

0.9626

0.9492

0.9964

0.9906

0.9842

0.9776

 

\(\hat {s}\)

0.0206

0.0212

0.0202

0.0172

0.0117

0.0112

0.0110

0.0097

α= 0.05

\(\hat {\alpha }\)

0.0525

0.0516

0.0483

0.0427

0.0555

0.0591

0.0555

0.0578

 

\(\hat {\rho }\)

0.9750

0.9598

0.9474

0.9368

0.9883

0.9821

0.9762

0.9707

 

\(\hat {s}\)

0.0394

0.0306

0.0251

0.0197

0.0246

0.0178

0.0148

0.0118

α= 0.1

\(\hat {\alpha }\)

0.1008

0.1006

0.0934

0.0878

0.1059

0.1071

0.1106

0.1050

 

\(\hat {\rho }\)

0.9610

0.9483

0.9380

0.9296

0.9806

0.9758

0.9709

0.9666

 

\(\hat {s}\)

0.0513

0.0358

0.0277

0.0210

0.0338

0.0219

0.0170

0.0130

α= 0.2

\(\hat {\alpha }\)

0.1985

0.1915

0.1843

0.1756

0.2062

0.2051

0.2033

0.2010

 

\(\hat {\rho }\)

0.9385

0.9320

0.9256

0.9204

0.9671

0.9663

0.9636

0.9610

 

\(\hat {s}\)

0.0663

0.0421

0.0307

0.0225

0.0464

0.0273

0.0198

0.0144

  

ρ= 0.99

   

ρ= 0.995

   

α = 0.01

\(\hat {\alpha }\)

0.0145

0.0244

0.0355

0.0491

0.0158

0.0320

0.0517

0.0856

 

\(\hat {\rho }\)

0.9993

0.9983

0.9969

0.9954

0.9996

0.9991

0.9983

0.9974

 

\(\hat {s}\)

0.0044

0.0031

0.0031

0.0028

0.0031

0.0020

0.0019

0.0017

α= 0.05

\(\hat {\alpha }\)

0.0680

0.0912

0.1153

0.1452

0.0764

0.1126

0.1587

0.2237

 

\(\hat {\rho }\)

0.9971

0.9961

0.9948

0.9935

0.9982

0.9978

0.9970

0.9963

 

\(\hat {s}\)

0.0103

0.0058

0.0047

0.0037

0.0076

0.0038

0.0030

0.0024

α= 0.1

\(\hat {\alpha }\)

0.1306

0.1579

0.1914

0.2323

0.1452

0.1900

0.2500

0.3291

 

\(\hat {\rho }\)

0.9946

0.9943

0.9933

0.9923

0.9966

0.9967

0.9961

0.9955

 

\(\hat {s}\)

0.0151

0.0077

0.0057

0.0043

0.0113

0.0052

0.0038

0.0027

α= 0.2

\(\hat {\alpha }\)

0.2376

0.2764

0.3133

0.3668

0.2550

0.3230

0.3834

0.4750

 

\(\hat {\rho }\)

0.9898

0.9914

0.9911

0.9907

0.9932

0.9948

0.9947

0.9945

 

\(\hat {s}\)

0.0226

0.0104

0.0072

0.0050

0.0174

0.0072

0.0048

0.0033

  1. The bolded values are \({\hat \alpha }\) within \(\pm 2 \sqrt {\alpha (1-\alpha)/M}\) and \({\hat \rho }\) within \(\pm 2 \sqrt {\rho (1-\rho)/M}\)