Valori critici per il test t di Student
 Tratta da: S.A. Glantz, Statistica per discipline bio-mediche, pag. 72-73 McGraw-Hill, Milano, 1988.
 
GL
p = 0,05
p = 0,01
GL
p = 0,05
p = 0,01
1
12,706
63,657
22
2,074
2,819
2
4,303
9,925
23
2,069
2,807
3
3,182
5,841
24
2,064
2,797
4
2,776
4,604
25
2,060
2,787
5
2,571
4,032
26
2,056
2,779
6
2,447
3,707
27
2,052
2,771
7
2,365
3,499
28
2,048
2,763
8
2,306
3,355
29
2,045
2,756
9
2,262
3,250
30
2,042
2,750
10
2,228
3,169
40
2,040
2,744
11
2,201
3,106
50
2,009
2,678
12
2,179
3,055
60
2,000
2,660
13
2,160
3,012
70
1,994
2,648
14
2,145
2,977
80
1,990
2,639
15
2,131
2,947
90
1,987
2,632
16
2,120
2,921
100
1,984
2,626
17
2,110
2,898
120
1,980
2,617
18
2,101
2,878
140
1,977
2,611
19
2,093
2,861
160
1,975
2,607
20
2,086
2,845
180
1,973
2,603
21
2,080
2,831
200
1,972
2,601
     
> 200
1,960
2,576
GL
p = 0,05
p = 0,01
GL
p = 0,05
p = 0,01