a

n

0.25

0.1

0.05

0.025

0.01

0.005

0.0025

0.001

0.0005

1

1.000

3.078

6.314

12.706

31.821

63.656

127.321

318.289

636.578

2

0.816

1.886

2.920

4.303

6.965

9.925

14.089

22.328

31.600

3

0.765

1.638

2.353

3.182

4.541

5.841

7.453

10.214

12.924

4

0.741

1.533

2.132

2.776

3.747

4.604

5.598

7.173

8.610

5

0.727

1.476

2.015

2.571

3.365

4.032

4.773

5.894

6.869

6

0.718

1.440

1.943

2.447

3.143

3.707

4.317

5.208

5.959

7

0.711

1.415

1.895

2.365

2.998

3.499

4.029

4.785

5.408

8

0.706

1.397

1.860

2.306

2.896

3.355

3.833

4.501

5.041

9

0.703

1.383

1.833

2.262

2.821

3.250

3.690

4.297

4.781

10

0.700

1.372

1.812

2.228

2.764

3.169

3.581

4.144

4.587

11

0.697

1.363

1.796

2.201

2.718

3.106

3.497

4.025

4.437

12

0.695

1.356

1.782

2.179

2.681

3.055

3.428

3.930

4.318

13

0.694

1.350

1.771

2.160

2.650

3.012

3.372

3.852

4.221

14

0.692

1.345

1.761

2.145

2.624

2.977

3.326

3.787

4.140

15

0.691

1.341

1.753

2.131

2.602

2.947

3.286

3.733

4.073

16

0.690

1.337

1.746

2.120

2.583

2.921

3.252

3.686

4.015

17

0.689

1.333

1.740

2.110

2.567

2.898

3.222

3.646

3.965

18

0.688

1.330

1.734

2.101

2.552

2.878

3.197

3.610

3.922

19

0.688

1.328

1.729

2.093

2.539

2.861

3.174

3.579

3.883

20

0.687

1.325

1.725

2.086

2.528

2.845

3.153

3.552

3.850

21

0.686

1.323

1.721

2.080

2.518

2.831

3.135

3.527

3.819

22

0.686

1.321

1.717

2.074

2.508

2.819

3.119

3.505

3.792

23

0.685

1.319

1.714

2.069

2.500

2.807

3.104

3.485

3.768

24

0.685

1.318

1.711

2.064

2.492

2.797

3.091

3.467

3.745

25

0.684

1.316

1.708

2.060

2.485

2.787

3.078

3.450

3.725

26

0.684

1.315

1.706

2.056

2.479

2.779

3.067

3.435

3.707

27

0.684

1.314

1.703

2.052

2.473

2.771

3.057

3.421

3.689

28

0.683

1.313

1.701

2.048

2.467

2.763

3.047

3.408

3.674

29

0.683

1.311

1.699

2.045

2.462

2.756

3.038

3.396

3.660

30

0.683

1.310

1.697

2.042

2.457

2.750

3.030

3.385

3.646

40

0.681

1.303

1.684

2.021

2.423

2.704

2.971

3.307

3.551

50

0.679

1.299

1.676

2.009

2.403

2.678

2.937

3.261

3.496

60

0.679

1.296

1.671

2.000

2.390

2.660

2.915

3.232

3.460

70

0.678

1.294

1.667

1.994

2.381

2.648

2.899

3.211

3.435

80

0.678

1.292

1.664

1.990

2.374

2.639

2.887

3.195

3.416

90

0.677

1.291

1.662

1.987

2.368

2.632

2.878

3.183

3.402

100

0.677

1.290

1.660

1.984

2.364

2.626

2.871

3.174

3.390

120

0.677

1.289

1.658

1.980

2.358

2.617

2.860

3.160

3.373