Calculate the Odds Ratio

R = ad / (bc)
The odds ratio compares the odds, if a property in two different groups is present or not. At 1, the odds are identical, if less than 1, the odds are bigger for the first group, if more than 1, the odds are bigger for the second group. The odds ratio is used e.g. in medicine to determine risk factors.

Group 1:	Property (a):	No property (b):
Group 2:	Property (c):	No property (d):
Odds ratio (R):

An example with invented numbers: women (group 1) and men (group 2) are checked for a certain disease. This occurs at 43 women (a=43) and doesn't at 3734 (b=3734). In contrast, 84 men (c=84) are affected, 3498 aren't (d=3498). The ratio is 0.48, which gives men a more than doubled chance to get this disease.


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