RD
(ridges per 25 mm2)

probability densities

likelihood ratio

posterior probability

male
P(RD /C)

female
P(RD /C')

P(C) = 0.5, P(C/RD)

P(C') = 0.5, P(C'/RD)

≤12

0.05

0.03

1.71

0.63

0.37

13

0.09

0.06

1.53

0.61

0.39

14

0.13

0.13

1.02

0.51

0.49

15

0.20

0.19

1.04

0.51

0.49

16

0.21

0.21

0.99

0.50

0.50

17

0.15

0.18

0.81

0.45

0.55

18

0.08

0.11

0.74

0.42

0.58

≥19

0.09

0.09

1.02

0.50

0.50

Table 2: Probability densities & likelihood ratios derived from observed RD in the ulnar area.