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Ivo D. Dinov, Ph.D. Assistant Professor in Statistics, Research Scientist, Department of Neurology, UCLA School of Medicine E-mail: ![]() ![]() |
T-table
The numbers in the body of the table indicate how large t must be in order for the result to be significant at the 0.05, 0.01, or 0.001 levels of significance. The alpha levels refer to the probabilities in both tails of the distributions. The last entry shows a df of infinity. With very large df, critical t values are the same as critical z values.
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df
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0.05
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0.01
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0.001
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1
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12.706
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63.656
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636.578
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2
|
4.303
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9.925
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31.600
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3
|
3.182
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5.841
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12.924
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4
|
2.776
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4.604
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8.610
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5
|
2.571
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4.032
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6.869
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6
|
2.447
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3.707
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5.959
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7
|
2.365
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3.499
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5.408
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8
|
2.306
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3.355
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5.041
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9
|
2.262
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3.250
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4.781
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10
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2.228
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3.169
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4.587
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11
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2.201
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3.106
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4.437
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12
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2.179
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3.055
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4.318
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13
|
2.160
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3.012
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4.221
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14
|
2.145
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2.977
|
4.140
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15
|
2.131
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2.947
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4.073
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16
|
2.120
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2.921
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4.015
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17
|
2.110
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2.898
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3.965
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18
|
2.101
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2.878
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3.922
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19
|
2.093
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2.861
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3.883
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20
|
2.086
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2.845
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3.850
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21
|
2.080
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2.831
|
3.819
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22
|
2.074
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2.819
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3.792
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23
|
2.069
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2.807
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3.768
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24
|
2.064
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2.797
|
3.745
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25
|
2.060
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2.787
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3.725
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26
|
2.056
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2.779
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3.707
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27
|
2.052
|
2.771
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3.689
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28
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2.048
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2.763
|
3.674
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29
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2.045
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2.756
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3.660
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30
|
2.042
|
2.750
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3.646
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31
|
2.040
|
2.744
|
3.633
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32
|
2.037
|
2.738
|
3.622
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33
|
2.035
|
2.733
|
3.611
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34
|
2.032
|
2.728
|
3.601
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35
|
2.030
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2.724
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3.591
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36
|
2.028
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2.719
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3.582
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37
|
2.026
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2.715
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3.574
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38
|
2.024
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2.712
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3.566
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39
|
2.023
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2.708
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3.558
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40
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2.021
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2.704
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3.551
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41
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2.020
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2.701
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3.544
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42
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2.018
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2.698
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3.538
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43
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2.017
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2.695
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3.532
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44
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2.015
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2.692
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3.526
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45
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2.014
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2.690
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3.520
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46
|
2.013
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2.687
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3.515
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47
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2.012
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2.685
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3.510
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48
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2.011
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2.682
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3.505
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49
|
2.010
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2.680
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3.500
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50
|
2.009
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2.678
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3.496
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51
|
2.008
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2.676
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3.492
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52
|
2.007
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2.674
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3.488
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53
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2.006
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2.672
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3.484
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54
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2.005
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2.670
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3.480
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55
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2.004
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2.668
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3.476
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56
|
2.003
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2.667
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3.473
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57
|
2.002
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2.665
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3.469
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58
|
2.002
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2.663
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3.466
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59
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2.001
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2.662
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3.463
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60
|
2.000
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2.660
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3.460
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61
|
2.000
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2.659
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3.457
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62
|
1.999
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2.657
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3.454
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63
|
1.998
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2.656
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3.452
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64
|
1.998
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2.655
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3.449
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65
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1.997
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2.654
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3.447
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66
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1.997
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2.652
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3.444
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67
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1.996
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2.651
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3.442
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68
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1.995
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2.650
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3.439
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69
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1.995
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2.649
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3.437
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70
|
1.994
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2.648
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3.435
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71
|
1.994
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2.647
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3.433
|
72
|
1.993
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2.646
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3.431
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73
|
1.993
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2.645
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3.429
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74
|
1.993
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2.644
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3.427
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75
|
1.992
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2.643
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3.425
|
76
|
1.992
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2.642
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3.423
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77
|
1.991
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2.641
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3.421
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78
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1.991
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2.640
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3.420
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79
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1.990
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2.639
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3.418
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80
|
1.990
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2.639
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3.416
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81
|
1.990
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2.638
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3.415
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82
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1.989
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2.637
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3.413
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83
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1.989
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2.636
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3.412
|
84
|
1.989
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2.636
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3.410
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85
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1.988
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2.635
|
3.409
|
86
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1.988
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2.634
|
3.407
|
87
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1.988
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2.634
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3.406
|
88
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1.987
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2.633
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3.405
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89
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1.987
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2.632
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3.403
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90
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1.987
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2.632
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3.402
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91
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1.986
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2.631
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3.401
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92
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1.986
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2.630
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3.399
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93
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1.986
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2.630
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3.398
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94
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1.986
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2.629
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3.397
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95
|
1.985
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2.629
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3.396
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96
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1.985
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2.628
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3.395
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97
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1.985
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2.627
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3.394
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98
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1.984
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2.627
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3.393
|
99
|
1.984
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2.626
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3.391
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100
|
1.984
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2.626
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3.390
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infinity |
1.960
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2.576
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3.290
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