128 BIOLOGICAL EFFECTS OF LOW LEVEL EXPOSURES
Table 7.4. Probability of Observing a Significantly Lower Risk in the Exposed Group, by Sample Size, Risk for Exposed Group, and Risk for
Comparison Group
Plsk fQr
Risk for Comparison Group
Exposed Group
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
A. Sample Size
=
25
in Each Group
0.50
0 0
0000
01
13
0.45
0
0
0000
0137
0.40
0
0
0000
1
37
13
0.35
0
0
0001
3
6
12
21
0.30
0
0
0
0
1
3
6
12
21
33
0.25
0
0
0
1
3
6
12
21
34
48
0.20
0
0
1
2
6
13
23
35
49
64
0.15
0
0
2
6
13
24
38
53
67
79
0.10
0
1
5
13
26
42
58
72
83
91
0.05
0
3
12
27
46
64
79
89
95
98
B. Sample Size
=
50
in Each Group
0.50
0
0
0
0
0
0
0
0
1
3
0.45
0
0
0000
0138
0.40 00
00001 38 1
9
0.35
0 0
0 0 0 1
39 20 36
0.30
0
0
0
0
1
3
10
21
38
57
0.25
0
0
0
1
3
9
22
41
61
78
0.20
0
0
1
3
10
23
42
64
81
92
0.15
0
0
3
11
26
46
67
84
94
98
0.10
0
2
12
31
54
75
89
96
99
100
0.05
1
13
39
66
85
95
99
100
100
100