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Table 19 Performance of parametric tolerance intervals based on the model selection approach for skewed distributions when the true distribution is Weibull

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

\(\hat {\alpha }\)

0.0069

0.0089

0.0065

0.0064

0.0074

0.0090

0.0066

0.0069

 

\(\hat {\rho }\)

0.9969

0.9971

0.9971

0.9975

0.9979

0.9981

0.9981

0.9984

 

\(\hat {s}\)

0.0325

0.0294

0.0325

0.0263

0.0280

0.0252

0.0293

0.0221

α= 0.05

\(\hat {\alpha }\)

0.0359

0.0364

0.0348

0.0322

0.0361

0.0372

0.0357

0.0330

 

\(\hat {\rho }\)

0.9870

0.9869

0.9878

0.9883

0.9916

0.9916

0.9922

0.9927

 

\(\hat {s}\)

0.0583

0.0573

0.0562

0.0526

0.0483

0.0466

0.0467

0.0426

α= 0.1

\(\hat {\alpha }\)

0.0726

0.0703

0.0646

0.0657

0.0746

0.0721

0.0655

0.0668

 

\(\hat {\rho }\)

0.9754

0.9755

0.9767

0.9770

0.9840

0.9840

0.9850

0.9853

 

\(\hat {s}\)

0.0781

0.0780

0.0756

0.0729

0.0642

0.0637

0.0621

0.0589

α= 0.2

\(\hat {\alpha }\)

0.1364

0.1331

0.1334

0.1324

0.1390

0.1353

0.1361

0.1351

 

\(\hat {\rho }\)

0.9537

0.9541

0.9556

0.9557

0.9692

0.9695

0.9708

0.9709

 

\(\hat {s}\)

0.1053

0.1051

0.1020

0.1006

0.0872

0.0872

0.0844

0.0823

  

ρ= 0.99

   

ρ= 0.995

   

α = 0.01

\(\hat {\alpha }\)

0.0075

0.0089

0.0070

0.0071

0.0072

0.0088

0.0069

0.0071

 

\(\hat {\rho }\)

0.9989

0.9990

0.9989

0.9992

0.9991

0.9992

0.9990

0.9994

 

\(\hat {s}\)

0.0214

0.0208

0.0255

0.0165

0.0190

0.0195

0.0243

0.0148

α= 0.05

\(\hat {\alpha }\)

0.0370

0.0371

0.0356

0.0338

0.0373

0.0370

0.0354

0.0338

 

\(\hat {\rho }\)

0.9958

0.9959

0.9961

0.9965

0.9966

0.9967

0.9968

0.9972

 

\(\hat {s}\)

0.0366

0.0342

0.0361

0.0311

0.0336

0.0313

0.0338

0.0283

α= 0.1

\(\hat {\alpha }\)

0.0742

0.0721

0.0666

0.0681

0.0737

0.0720

0.0660

0.0680

 

\(\hat {\rho }\)

0.9920

0.9920

0.9925

0.9930

0.9935

0.9936

0.9940

0.9944

 

\(\hat {s}\)

0.0475

0.0459

0.0461

0.0421

0.0434

0.0416

0.0424

0.0381

α= 0.2

\(\hat {\alpha }\)

0.1397

0.1369

0.1363

0.1357

0.1397

0.1367

0.1364

0.1359

 

\(\hat {\rho }\)

0.9843

0.9844

0.9854

0.9856

0.9873

0.9874

0.9882

0.9885

 

\(\hat {s}\)

0.0638

0.0634

0.0619

0.0588

0.0578

0.0572

0.0563

0.0529

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