= .995

.99

.975

.95

.90

.80

.75

.70

.60

.55

01

63.66

31.82

12.71

6.31

3.08

1.376

1.000

.727

.325

.158

02

9.92

6.96

4.30

2.92

1.89

1.061

.816

.617

.289

.142

03

5.84

4.54

3.18

2.35

1.64

.978

.765

.584

.277

.137

04

4.60

3.75

2.78

2.13

1.53

.941

.741

.569

.271

.134

05

4.03

3.36

2.57

2.02

1.48

.920

.727

.559

.267

.132

06

3.71

3.14

2.45

1.94

1.44

.906

.718

.553

.265

.131

07

3.50

3.00

2.36

1.90

1.42

.896

.711

.549

.263

.130

08

3.36

2.90

2.31

1.86

1.40

.889

.706

.546

.262

.130

09

3.25

2.82

2.26

1.83

1.38

.883

.703

.543

.261

.129

10

3.17

2.76

2.23

1.81

1.37

.879

.700

.542

.260

.129

11

3.11

2.72

2.20

1.80

1.36

.876

.697

.540

.260

.129

12

3.06

2.68

2.18

1.78

1.36

.873

.695

.539

.259

.128

13

3.01

2.65

2.16

1.77

1.35

.870

.694

.538

.259

.128

14

2.98

2.62

2.14

1.76

1.34

.868

.692

.537

.258

.128

15

2.95

2.60

2.13

1.75

1.34

.866

.691

.536

.258

.128

16

2.92

2.58

2.12

1.75

1.34

.865

.690

.535

.258

.128

17

2.90

2.57

2.11

1.74

1.33

.863

.689

.534

.257

.128

18

2.88

2.55

2.10

1.73

1.33

.862

.688

.534

.257

.127

19

2.86

2.54

2.09

1.73

1.33

.861

.688

.533

.257

.127

20

2.84

2.53

2.00

1.72

1.32

.860

.687

.533

.257

.127

21

2.83

2.52

2.08

1.72

1.32

.859

.686

.532

.257

.127

22

2.82

2.51

2.07

1.72

1.32

.858

.686

.532

.256

.127

23

2.81

2.50

2.07

1.71

1.32

.858

.685

.532

.256

.127

24

2.80

2.49

2.06

1.71

1.32

.857

.685

.531

.256

.127

25

2.79

2.48

2.06

1.71

1.32

.856

.684

.531

.256

.127

26

2.78

2.48

2.06

1.71

1.32

.856

.684

.531

.256

.127

27

2.77

2.47

2.05

1.70

1.31

.855

.684

.531

.256

.127

28

2.76

2.47

2.05

1.70

1.31

.855

.683

.530

.256

.127

29

2.76

2.46

2.04

1.70

1.31

.854

.683

.530

.256

.127

30

2.75

2.46

2.04

1.70

1.31

.854

.683

.530

.256

.127

40

2.70

2.42

2.02

1.68

1.30

.851

.681

.529

.255

.126

60

2.66

2.39

2.00

1.67

1.30

.848

.679

.527

.254

.126

120

2.62

2.36

1.98

1.66

1.29

.845

.677

.526

.254

.126

2.58

2.33

1.96

1.645

1.28

.842

.674

.524

.253

.126

[ = 0.975 represents 95% confidence interval. ]