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Table 34 Performance of tolerance intervals based on Weibull distribution when the true distribution is gamma (G: Weibull; 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

\(\hat {\alpha }\)

0.0074

0.0040

0.0020

0.0003

0.0106

0.0084

0.0055

0.0015

 

\(\hat {\rho }\)

0.9948

0.9875

0.9784

0.9681

0.9975

0.9947

0.9907

0.9857

 

\(\hat {s}\)

0.0177

0.0162

0.0154

0.0137

0.0116

0.0094

0.0088

0.0080

α= 0.05

\(\hat {\alpha }\)

0.0307

0.0185

0.0090

0.0026

0.0384

0.0276

0.0195

0.0110

 

\(\hat {\rho }\)

0.9844

0.9761

0.9674

0.9584

0.9919

0.9888

0.9849

0.9804

 

\(\hat {s}\)

0.0330

0.0242

0.0200

0.0162

0.0227

0.0150

0.0122

0.0099

α= 0.1

\(\hat {\alpha }\)

0.0570

0.0334

0.0180

0.0082

0.0714

0.0509

0.0379

0.0245

 

\(\hat {\rho }\)

0.9753

0.9682

0.9606

0.9529

0.9866

0.9845

0.9812

0.9773

 

\(\hat {s}\)

0.0426

0.0288

0.0224

0.0174

0.0300

0.0184

0.0141

0.0110

α= 0.2

\(\hat {\alpha }\)

0.1054

0.0661

0.0412

0.0208

0.1283

0.0986

0.0704

0.0491

 

\(\hat {\rho }\)

0.9608

0.9571

0.9518

0.9460

0.9779

0.9783

0.9761

0.9733

 

\(\hat {s}\)

0.0547

0.0342

0.0253

0.0189

0.0397

0.0227

0.0164

0.0122

  

ρ= 0.99

   

ρ= 0.995

   

α = 0.01

\(\hat {\alpha }\)

0.0183

0.0231

0.0280

0.0359

0.0218

0.0318

0.0439

0.0707

 

\(\hat {\rho }\)

0.9992

0.9988

0.9979

0.9966

0.9994

0.9993

0.9988

0.9980

 

\(\hat {s}\)

0.0058

0.0036

0.0031

0.0028

0.0047

0.0026

0.0021

0.0019

α= 0.05

\(\hat {\alpha }\)

0.0646

0.0743

0.0812

0.0992

0.0752

0.0995

0.1259

0.1794

 

\(\hat {\rho }\)

0.9971

0.9970

0.9961

0.9949

0.9979

0.9981

0.9976

0.9968

 

\(\hat {s}\)

0.0123

0.0064

0.0048

0.0038

0.0101

0.0048

0.0034

0.0027

α= 0.1

\(\hat {\alpha }\)

0.1111

0.1236

0.1348

0.1551

0.1281

0.1615

0.1972

0.2591

 

\(\hat {\rho }\)

0.9950

0.9955

0.9949

0.9938

0.9964

0.9970

0.9967

0.9961

 

\(\hat {s}\)

0.0169

0.0083

0.0058

0.0044

0.0140

0.0064

0.0043

0.0031

α= 0.2

\(\hat {\alpha }\)

0.1916

0.2031

0.2188

0.2484

0.2170

0.2515

0.3006

0.3778

 

\(\hat {\rho }\)

0.9913

0.9932

0.9930

0.9923

0.9935

0.9954

0.9955

0.9951

 

\(\hat {s}\)

0.0232

0.0109

0.0072

0.0051

0.0195

0.0085

0.0054

0.0037

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